John 13:12 - Clarke's commentary and critical notes on the Bible

So after he had washed their feet, and had taken his garments, and was set down again, he said unto them, Know ye what I have done to you? Know ye what I have done - Our Lord had told Peter, in the presence of the rest, John 13:7, that he should afterwards know what was the intent and meaning of this washing; and now he begins to fulfill his promise; therefore I think it more likely that he gives a command, here, than asks a question, as he knew himself that they did not comprehend his design. On this account γινωσκετε might be translated in the imperative mood, Consider what I have done.