The linen which he spreads on the crown of your head denotes the freedom to which you have been called. You were before standing bareheaded, as this is the habit of the exiles and the slaves, but after you have been signed he throws on your head linen, which is the emblem of the freedom to which you have been called. Men such as these (=freemen) are in the habit of spreading linen on their heads, and it serves them as an adornment both in the house and in the market-place. — Theodore of Mopsuestia, Liber ad baptizandos.
While scanning the English translation of Theodore’s sermons to those awaiting baptism (now online here), I came across this interesting statement, that during the ceremony of manumission the ex-slave’s head was covered; and thus that being bare-headed was a mark of a slave.
I wonder how this relates to the oft-mocked injunction of Paul, that women should cover their heads, particularly since female slaves and prostitutes could be interchangeable.