John 13:4
“And having risen from supper, and laid aside His garments.”
2. Observe how not by the washing only, but in another way also He exhibits humility. For it was not before reclining, but after they had all sat down, then He arose. In the next place, He does not merely wash them, but does so, putting off His garments. And He did not even stop here, but girded Himself with a towel. Nor was He satisfied with this, but Himself filled (the basin), and did not bid another fill it; He did all these things Himself, showing by all that we must do such things, when we are engaged in well doing, not merely for form's sake, but with all zeal. Now He seems to me to have washed the feet of the traitor first from its saying,
Source: Homilies on the Gospel of John (New Advent)