The Evangelist inserts this as if in astonishment: our Lord being about to wash the feet of the very person who had resolved to betray Him. It shews the great wickedness too of the traitor, that even the partaking of the same table, which is a check to the worst of men, did not stop him.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Hom. lxx. 1