Charles Ellicott Commentary John 13:14

"If I then, the Lord and the Teacher, have washed your feet, ye also ought to wash one another`s feet." — John 13:14 (ASV)

You ought also to wash one another’s feet.—The argument is à fortiori. If He had so humbled Himself as to do the work of a servant for them, much more they ought to humble themselves for each other. To make his words as striking as possible, they are prefaced by the emphatic I, and “Master and Lord” is repeated from the previous verse, but in the inverse order, to give special prominence to the word of greater dignity.