I’m trying to find some specific sources for the claim that the Caliph Omar ordered the burning of the library at Alexandria. Yesterday we looked at Abd al-Latif. The source most commonly quoted is Gregory Bar Hebraeus, also known as Abu’l Faraj, writing in the 13th century. He was the last great writer of Syriac.
Bar Hebraeus wrote two histories in Syriac; the Chronicum Syriacum, and the Chronicum Ecclesiasticum. The former is more or less a world history, and was translated by E. Wallis Budge. The latter is a list of ecclesiastics, of both the west and east Syriac churches, and has only been translated into Latin.
Late in life, however, he produced a history in Arabic, which was extracted and translated from the Chronicum Syriacum, with additions specific to the Arabic version. Excerpts from this were printed in Latin translation by the 17th century orientalist, Edward Pococke, in 1650, (an 1806 reprint is here)  and then the Arabic text with a Latin translation of the whole by the same editor in 1663 under the title Historia Compendiosa Dynastiarum .
In the 1650 text, on p.170-171 he quotes Bar Hebraeus. But I find that I have a PDF of the 1663 edition, and so I have transcribed the Latin from it. The following text is on p.114 (p.66 of the PDF). I would guess that the PDF comes from the Early English Books Online (or EEBO) database, accessible only behind a paywall, but I don’t know. I would guess that the volume also included the Arabic, which explains a page number of 181; but I don’t seem to have this.
Porro hoc tempore claruit inter Muslemios Johannes, quem vocamus nos Grammaticum, qui Alexandrinus fuit, fidemque Christianorum Jacobiticorum professus Severi doctrinam adstruebat, deinde recessit ab eo quod profitentur Christiani de Trinitate; quare convenientes eum Episcopi in urbe Metsra rogarunt, ut ab eo quod [profitebatur] rediret; cumque redire nollet, eum de gradu suo dejecerunt. Vixitque donec caperet Amrus Ebno’lAs Alexandriam, et ad Amrum, accessit; qui, cognito quem inscientiis locum teneret, honore ipsum affecit, audiitque de sermonibus eius Philosophicis, quibus assueti non fuerant Arabes, quod eum a stuporem redigeret, quoque percelleretur. Fuit autem Amrus intellectu praeditus, ad res percipiendas promptus, conceptibus claris, adhaesit ergo illi, neque ab eo discessit. Deine die quodam dixit illi Johannes, “Circumvisti tu omnia Alexandriae repositoria, omniaque rerum genera quae in iis reperiuntur obsignasti; quod ad illa igitur, quae tibi profutura sint, nolo tibi contradicere, at quae nulli tibi usui futura sunt, nobis potius convenient.” Dixit illi Amrus, “Quid est quo opus tibi sic,” dixit illi; [p.181] “Libri Philosophici, qui in Gazophylaciis [Bibliothecis] Regiis reperiuntur.” “Hoc,” inquit Amrus, “est de quo statuere, non possum. Illud [petis] de quo ego quid in mandatis dare non possum, nisi post veniam ab Imperatore fidelium Omaro Ebno’lchatsab impetratam.” Scriptis ergo ad Omarum literis, notum ei fecit, quid dixisset Johannes, perlataeque sunt ad ipsum ab Omaro literae, in quibus scripsit, “Quod ad libros quorum mentionem fecisti: si in illis contineatur, quod cum libro Dei conveniat, in libro Dei [est] quod sufficiat absque illo; quod si in illis fuerit quod libro Dei repugnet, neutiquam est eo [nobis] opus, jube igitur e medio tolli.” Jussit ergo Amrus Ebno’lAs dispergi eos per balnea Alexandriae, atque illis calefaciendis comburi; ita spatio semestri consumpti sunt. Audi quid factum fuerit et mirare. E medicis autem qui hoc tempore floruerunt fuit Paulus Aeginata Medicus, suo tempore celebris: …
I do not guarantee the accuracy of the above, from the wretched PDF. But it more or less corresponds to the following translation I found online at an Islamic site here. I have resisted the urge to tidy it up, as this probably originates from the Arabic text rather than the Latin above.
In those days Yahya al-Nahwi, who was known as Grammaticus in our language, enjoyed fame among Arabs. He was a resident of Alexandria and a Jacobite Christian who ascribed to the Savari (?) creed. In his last days he renounced the Christian faith, and all Christian scholars of Egypt gathered around him and advised him to recant, but he did not. When the scholars were disappointed they stripped him of all the offices that he held. He lived in that condition until Amr ibn al As (the Muslim commander of the army conquering Egypt) entered Egypt.
One day Yahya went to see him. Amr came to know about his learning and scholarship and he paid him great respect. He began a discourse on philosophical issues which were unknown to Arabs: His speech made a deep impression on Amr and he became fond of him. As Amr was an intelligent, wise and thoughtful man, he made Yahyaa his companion, never parting his company.
One day Yahya said to Amr, “Whatever there is in Alexandria is in your control. As to things that are useful for you we have nothing to do with them, but as to those which you may not need, my request is that you favour us by putting them at our disposal, for we deserve them more than anyone else.” Amr asked him what they were. He said: “They are the books on wisdom and philosophy that are stored in the state library”
Amr replied that he could not decide the matter himself but had to seek the Caliph’s instructions in this regard. Accordingly, he informed the Caliph of the matter and asked for instructions. The Caliph wrote: “If those books are in agreement with the Quran, we have no need of them; and if these are opposed to the Quran, destroy them.”
After receiving the reply Amr began dismantling the library. At his orders, the books were distributed among the public baths of Alexandria. Thus in a period of complete six months all the books were burnt and destroyed. Believe it, and do not be amazed. 
“Savari” is of course the Severan form of monophysitism. The translation is rather free, tho, I can see, so let’s return to Pococke’s Latin and look at the key point:
Scriptis ergo ad Omarum literis, notum ei fecit, quid dixisset Johannes, perlataeque sunt ad ipsum ab Omaro literae, in quibus scripsit, “Quod ad libros quorum mentionem fecisti: si in illis contineatur, quod cum libro Dei conveniat, in libro Dei [est] quod sufficiat absque illo; quod si in illis fuerit quod libro Dei repugnet, neutiquam est eo [nobis] opus, jube igitur e medio tolli.” Jussit ergo Amrus Ebno’lAs dispergi eos per balnea Alexandriae, atque illis calefaciendis comburi; ita spatio semestri consumpti sunt. Audi quid factum fuerit et mirare.
Therefore having written a letter to Omar, he told him what John said, and a letter was brought to him from Omar, in which he (Omar) wrote, “About the books of which you have made mention: if there is contained in them what agrees (conveniat) with the book of God, in the book of God is what is sufficient, without them; but if (quodsi) in them there is what the book of God rejects, by no means is the material in them for us, order them to be taken away.” Therefore Amr ibn al-As ordered to disperse them among the baths of Alexandria, and to burn them for heating; so in the space of six months they were consumed. Listen to what was done, and marvel.
This does not seem to quite say what Omar is generally supposed to say, unless I have misunderstood the Latin. Unfortunately the words as quoted vary very considerably online: “they will either contradict the Koran, in which case they are heresy, or they will agree with it, so they are superfluous” is merely one of these.
I wonder just what the English language source is, never mind the ancient source. I tried to find something in Gibbon, but in vain.
But using these words, I find this page which makes the following claim, helpfully escaping from the morass of hearsay by giving a reference to a real journal article:
We think that Isya Joseph did a thorough investigation of Bar Hebraeus and his role in the narrations about the Alexandria Library destruction by Amr Ibn Al-As on the command of Omar. His research was published in 1911 in The American Journal of Semitic Languages and Literature (Volume 27). Here is a link to his research.
The reader is advised to read pages 335-8. According to Isya Joseph, Bar Hebraeus says that Yahya, a Coptic philosopher, petitioned Amr Ibn Al-As to restore the royal library (Alexandria Library). Amr referred the matter to Omar. Omar ordered him to destroy the library on grounds that if what is in the library agrees with the contents of the Qur’an, then it is redundant. And, if the contents of the library do not agree with the Qur’an, then such contents are heretic. …
The assumption here is that no Muslim mentioned this library incident before Hebraeus. This latter assumption is actually mistaken. There are at least two independent sources that validate Hebraeus’s story. First, Abd-Al-Latif of Baghdad visited Egypt in the latter part of the sixth century. He mentions that the library which was in Alexandria was burned by Umru bn al-As in compliance to Omar’s orders. Second, Jamal Ad-din Al-Kufti, who was born in Kuft in upper Egypt in 565 A. H., and died in 646 A. H. , declares that the library was burned by Umru Ibn Al-As (page 335 of the above linked article).
When I look at this article by Isya Joseph, it begins with the following words:
In his At-târih (ed. 1663, p. 180), Bar Hebraeus says that when Yahya, the Coptic philosopher, petitioned Umru bn-Al-`As, the Moslem conqueror of Egypt, to restore the Royal Library to the public, the latter referred the matter to Omar bn-Al Hattab, the second Halif. The Halif ordered him to destroy the Library on the ground that if the books were in accord with the Kuran, the Kuran alone was sufficient, and if at variance with it, there was no need of them; therefore they were to be done away with.
The page number agrees with the data above. This phrase “in accord with the Kuran”, modified to “in accordance with” appears in various places. Dr Joseph tells us more; that his source is George Zaidan, who he tells us published in 1904 in Cairo a History of Mohammedan Civilization. He refers to vol. III of this, and continues:
The other authority is Jamal ad-Din Al-Kufti, wazir of Aleppo, who was born in Kuft in upper Egypt (south of Asiut) in 565 A.H., and died in 646 A.H. (op. cit., p. 42). In his Dictionary of Learned Men, a manuscript in the Hidewi Library, dating from 1197 A.H., Ibn Al-Kufti declares that the Library was burned by Umru bn Al-`As.
I don’t know whether we can access the work of Jamal ad-Din al-Kufti, which was clearly unpublished at that time. My own knowledge of Islamic literature is too scanty to say, and a web search drew a blank. Does anyone know?
The remainder of Dr Joseph’s article merely summarises material from Zaidan. Doubtless the book was one difficult to access in America at that period. I wonder whether Zaidan’s book is online. I find his name given as Jirgi Zaydan, Zeidan, etc. A search under the former gives a list of Arab publications. It seems that Zaidan published in Arabic; volume IV was translated into English by David Margoliouth, and is online here, but of course that does not help us. So Zaidan is also a dead end.
Returning to the Islamic site al-Tawid, the page also gives a further interesting quote (which it then disagrees with):
4) Ibn Khaldun, in the chapter “On the Rational Sciences and their Kinds” (al-`ulum al-’aqliyyah wa asnafuha) of his Muqaddimah, says: “At the time of the conquest of Iran many books of that country fell into the hands of the Arabs. Sa’d ibn Abi al-Waqqas wrote to `Umar ibn al-Khattab asking his permission to have them translated for Muslims. ‘Umar wrote to him in reply that he should cast them into water, “for if what is written in those books is guidance, God has given us a better guide; and if that which is in those books is misleading, God has saved us from their evil.” Accordingly those books were cast into water or fire, and the sciences of the Iranians that were contained in them were destroyed and did not reach us.
This he references as “Pur Dawud, Yashtha, vol. ii, p. 20″; but he then rebuts the statement by examining Ibn Khaldun directly who in fact introduces the quote as follows: “It is said that these sciences reached Greece from the Persians, when Alexander killed Darius and conquered Persia, getting access to innumerable books and sciences developed by them. And when Iran was conquered (by Muslims) and books were found there in abundance, Sa’d ibn Abi Waqqas wrote to `Umar . . . .”
Is Ibn Khaldun accessible, I wonder?
Just to follow up on yesterday’s post, the Islamic web page also quotes Abd al-Latif, whom he describes as a Christian writer, in a somewhat curious form:
Abd al-Latif al- Baghdad, a Christian, refers to it in his book entitled al Ifadah wa al-Nibar fi al-umur al-mushahadah wa al-hawadih al-mu`ayanah fi `ard Misr (the subject of the book is the events and conditions observed personally by the author, and is in fact, a travel account). In it while describing a `tower’ ( `amud) known as `Amad al-Sawari, the previous site of the library of Alexandria, he writes: “It is said that this tower is one of the several on which was erected a theatre, where Aristotle used to lecture and which was an academy, and here stood the library of Alexandria which was burnt by Amr ibn al-`As at the Caliph’s order.”
Whether this version or de Sacy’s is right I cannot say unless we obtain the Arabic text. Isya Joseph also has a version of Abd al-Latif, referenced to vol. III, pp.41 ff of Zaidan. He does not quote him explicitly, but says:
In speaking of the past events and remains in Egypt, he says that the Library which was in Alexandria was burned by Umru bn Al-`As in compliance with the order of Omar.
As we saw yesterday, this is almost the words of Abd al-Latif, word for word.
There are several loose ends in all this. The lack of modern editions and modern translations is a clear barrier. I was able to find a short bibliography here.
 Bar Hebraeus, (tr. Edward Pococke). Specimen Historiae Arabvm; sive, Gregorii Abul Farajii Malatiensis De origine & moribus Arabum succincta narratio, in linguam latinam conversa, notisque è probatissimis apud ipsos authoribus, fusiùs illus., operâ & studio Edvardi Pocockii. Oxoniae: 1650: excudebat H. Hall.
 Bar Hebraeus (=Abu’l Faraj) (tr. Edward Pococke) . Historia Compendiosa Dynastiarum Authore Gregorio abul-Pharajio Malatiensi Medico, Historiam Complectens Universalem, a Mundo Condito, Usque Ad Tempora Authoris, Res Orientalium Accuratissime Describens Arabice Edita & Latine Versa Ab Edvardo Pocockio. Imprint: Oxford: H. Hall / Ric. Davis, 1663.
 According to the website this is Wahid Akhtar (tr), Murtada Mutahhari-quddisa sirruh, Alleged Book Burnings in Iran and Egypt: A Study of Related Facts and Fiction, in al Tawhid vol 14, No. 1 Spring 1997, and an English translation from the Persian. The site refers to Bar Hebraeus as Abu Al-Faraj ibn al-`Ibri. He introduces the author, mentions the Chronicum Syriacum, and adds “He also prepared a condensed version of it in Arabic under the title Mukhtasar al-duwal. It is said that all its manuscripts are incomplete and defective.” It references the information as “35. These details are cited from Shibli Nu’mani’s Kitabkhaneh yi Iskandariyyah, Persian trans. by Fakhr-e Da`i, pp. 14-15, 38.” and “36. Ibid., pp. 16-18.”