The Meaning of the Act: the One Exception. The disciples recognise in Him their teacher and master. They should, therefore, follow His example by helping each other even in the lowliest services. The Master had set an example which the slave need not be ashamed to copy. If they realise that by doing such things He has made it their duty to do the same, then they will be happy in the doing of them. He returns to the theme of the traitor. He knows, as they do not, the character of each disciple whom He has chosen. But it had to be. The Scripture must be fulfilled (Psalms 41:9). He has warned them, that when the event happens, instead of being discouraged, they may recognise in the fulfilment of prophecy a proof of what He is. In John 13:20 the author adds that acts of humility will not degrade them, but prove them to be His messengers, to whom all honour is due.
John 13:12-20
12 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?
13 Ye call me Master and Lord: and ye say well; for so I am.
14 If I then, your Lord and Master, have washed your feet; ye also ought to wash one another's feet.
15 For I have given you an example, that ye should do as I have done to you.
16 Verily, verily, I say unto you, The servant is not greater than his lord; neither he that is sent greater than he that sent him.
17 If ye know these things, happy are ye if ye do them.
18 I speak not of you all: I know whom I have chosen: but that the scripture may be fulfilled, He that eateth bread with me hath lifted up his heel against me.
19 Nowb I tell you before it come, that, when it is come to pass, ye may believe that I am he.
20 Verily, verily, I say unto you, He that receiveth whomsoever I send receiveth me; and he that receiveth me receiveth him that sent me.