John Cassian, The Institutes I.10: Of the modification in the observances which may be permitted in accordance with the character of the climate or the custom of the district

Of the modification in the observances which may be permitted in accordance with the character of the climate or the custom of the district.

So much may be said, that we may not appear to have left out any article of the dress of the Egyptians. But we need only keep to those which the situation of the place and the customs of the district permit. For the severity of the winter does not allow us to be satisfied with slippers or tunics or a single frock; and the covering of tiny hoods or the wearing of a sheepskin would afford a subject for derision instead of edifying the spectators. Wherefore we hold that we ought to introduce only those things which we have described above, and which are adapted to the humble character of our profession and the nature of the climate, that the chief thing about our dress may be not the novelty of the garb, which might give some offence to men of the world, but its honourable simplicity.