Explanations of biblical passages form quite a portion of the letters.
1243 (IV.48) TO AMMONIUS
For fear of presumption, a terrible ill from which one can escape with difficulty, lest we remain on earth and be deprived of the heavenly rewards, the Lord said: “Now let us leave this place!” [John 14:31] Indeed, having engaged His own power in the word which He spoke, He delivered his true disciples from tyrannical passions and made them pass into the celestial assembly.
The French editor, Pierre Evieux, tells is that the following letter is also preserved in the catenas on Romans found in two manuscripts, Vatican. gr. 762 (10th c.) and Vienna. Theol. gr. 166 (14th c.).
In Romans 1:32, Paul condemns people who, not merely commit a sin, but even approve of those who do the same. Theologios queries why it is wrong to consider those who encourage sin in others as worse than those who actually commit the sin themselves. Isidore’s reply is interesting as showing that some were willing to suppose a corruption in the text here.
1244 (IV.60) TO THEOLOGIOS THE DEACON
Since you’ve provided us the occasion to return to the apostolic treasures — in fact you said: ‘It says “Not only do they do this, but also they approve of those who do this” [Rom. 1:32] and you added: If the approval is worse than the action itself, why did Paul adopt this order [of words] here?’ — call a little upon your good sense to work out the sense of the apostolic saying which is escaping you, and listen.
There are some people who did not understand the quotation but which, being embarassed like yourself and supposing that the apostolic expressions are corrupt, have interpreted them this manner: “Not only are there those who do this, but also those who approve those who do this.” According to them, the primitive text was presented thus to make it understood that the action was the more serious and approval of it less serious. For me, without saying that the apostolic books display an error in this passage, without siding either with those who did not understand — because perhaps, even if they are wrong on this passage, on others they are right, and they have caught the direction of passages that, for my part, I did not manage to understand — I will set out what I understood and will allow the judgement of the readers to decide if I am right.
So, in my opinion, it is because to praise the culprits is much more wong and more serious from the point of view of the punishment that this sentence is relevant: ”Not only do they do this, but also they approve of those who do this.” Because he who condemns his sin after the misdeed will be able in time to repent one day, finding the judgment of the sin a very great help in changing his attitude; while he who speaks in praise of the evil will deprive himself of the help which repentance procures. So because this judgement concerns a corrupt conscience and a heart tainted with an incurable disease, he who speaks in praise of the fault of the culprit is rightly judged more culpable. Because the one will very quickly be diverted from sin, the other not at all, according to whether the judgement relates to he who commits the misdeed or he who approves it.