The first sentence of this verse represents a Greek clause, which indicates fact, rather than condition or supposition as “If…” might imply in English (Revised Standard Version “If I then, your Lord and Teacher, have washed your feet…”). Accordingly, Good News Translation renders it simply as a statement: I, your Lord and Teacher, have just washed your feet. Jesus is using here a recognized rabbinical type of argument, which moves from the greater to the lesser. If the greater (the Lord and Teacher) has done a certain thing, then the lesser (the disciples) are obligated to do the same. It should be noted that, while in verse 13 the order is Teacher and Lord, in this verse the order is Lord and Teacher.

Though the implied condition between the first and second halves of verse 14 may be clear in some languages, it may be necessary in others to make the relation more specific, while at the same time not making the construction too difficult, for example, “I am your Lord and your Teacher, and yet I have just washed your feet. Since I have done that to you, you should wash one another’s feet.”

The Greek verb here translated should appears again in 19.7; there it is translated ought.

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .