Charles Ellicott Commentary John 13:5

"Then he poureth water into the basin, and began to wash the disciples` feet, and to wipe them with the towel wherewith he was girded." — John 13:5 (ASV)

After that he poureth water into a bason.—Better, . . . into the basin. It was the basin in the room, commonly used, and now ready for such purposes. The water was at hand. All suggested then that one of the disciples might have performed this act which the Lord now performs. That it was commonly regarded as an act of reverence from an inferior to a superior is made clear by the Rabbinical passages quoted here by Schottgen and Lightfoot. (Compare to the note on Luke 7:44.)

And began to wash the disciples’ feet.—The exactness of the narrative notes that the act was only begun, and was interrupted by the objection of Peter. This word “began” is frequent in the earlier Gospels, but it is only in this touch of accuracy that St. John uses it.