John 13:4-5
¹Now before the feast of the passover, when Jesus knew that his hour was come that he should depart out of this world unto the Father, having loved his own which were in the world, he loved them unto the end.

⁴He riseth from supper, and laid aside his garments; and took a towel, and girded himself.
⁵After that he poureth water into a bason, and began to wash the disciples' feet, and to wipe them with the towel wherewith he was girded.

¹³Ye call me Master and Lord: and ye say well; for so I am.
¹⁴If I then, your Lord and Master, have washed your feet; ye also ought to wash one another's feet. 
¹⁵For I have given you an example, that ye should do as I have done to you. 
¹⁶Verily, verily, I say unto you, The servant is not greater than his lord; neither he that is sent greater than he that sent him.

Galatians 5:13
¹³For, brethren, ye have been called unto liberty; only use not liberty for an occasion to the flesh, but by love serve one another.