John 13:11-14

For He knew who would betray Him; therefore He said, “You are not all clean.” 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.