After that, He poured water into a basin and began to wash the disciples' feet, and to wipe them with the towel with which He was girded... 

So when He had washed their feet, taken His garments, and sat down again, He said to them, "Do you know what I have done to you?  You call me Teacher and Lord, and you say well, for so I am.  If I then, your Lord and Teacher, have washed your feet, you also ought to wash one another's feet.  For I have given you an example, that you should do as I have done to you."

Jn 13:5-15   (NKJV)