"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? Ye call me Master and Lord: and ye say well; for so I am. If I then, [your] Lord and 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 servant is not greater than his lord; neither he that is sent greater than he that sent him. If ye know these things, happy are ye if ye do them." —John 13:12-17
Brother Will says: Jesus rarely speaks from a position of authority—he tends to call himself a "child of humanity" or a "child of God" to show he's just like the rest of us. But here, he uses the disciples' insistance that he's their Lord and Master to say, "Fine, have it your way, I'm your lord and master. I'm still here to serve, and if you truly respect me at all, you'll serve others also." Jesus uses authority to reject authority, which is the proper use of authority.