John 13:12-16

So after he had washed their feet and had taken his garments and had sat down again, he said unto them, Know ye what I have done to you? Ye call me Master and Lord; and ye say well, for so I am. If I then, the Lord and the Master, have washed your feet, ye also ought to wash one another’s feet. For I have given you an example that ye should do as I have done to you. Verily, verily, I say unto you, The slave is not greater than his lord; neither is the apostle greater than he that sent him.