so he got up from the meal, took off his outer clothing, and wrapped a towel round his waist.

Depending upon the timing of the Lukan passage, Jesus may have already rebuked the apostles for trying to get the best seats at the beginning of the meal (Luke 22:24-30) and He now gives them a living parable to illustrate His point even further.

Luke 22:24-30  Also a dispute arose among them as to which of them was considered to be greatest.  Jesus said to them, “The kings of the Gentiles lord it over them; and those who exercise authority over them call themselves Benefactors.  But you are not to be like that. Instead, the greatest among you should be like the youngest, and the one who rules like the one who serves.  For who is greater, the one who is at the table or the one who serves? Is it not the one who is at the table? But I am among you as one who serves.  You are those who have stood by me in my trials.  And I confer on you a kingdom, just as my Father conferred one on me,  so that you may eat and drink at my table in my kingdom and sit on thrones, judging the twelve tribes of Israel.

“got up” = from reclining at the table. Remember that the meal is already in progress (verse 13:2). The first cup has already been consumed and the next part of the Passover was the first of the ritual handwashings. The second handwashing would be done by all present, but this first handwashing was to be done by the Head of the Company alone immediately following the first cup.

John 13:2  The evening meal was being served, and the devil had already prompted Judas Iscariot, son of Simon, to betray Jesus.

The disciples would not have been surprised when Jesus got up, but they must have wondered when He took off His outer garments, put on the towel, and filled the basin with water, like a slave who was about to do the lowest of all jobs.

This incident must have been foremost in Peter’s mind when years later he wrote (1 Peter 5:5).

1 Peter 5:5  Young men, in the same way be submissive to those who are older. All of you, clothe yourselves with humility towards one another, because, “God opposes the proud but gives grace to the humble.”