"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" (Jn. 13:12-15).
Note that two words in these verses are in italics. That is because they were not in the original Greek text. They were added by the translators "for clarity." Like most of their efforts to do so, by adding something, which is "frowned upon" in the Scriptures, by the way (Rev. 22:18-19), they actually obscure some great truth! Let's read those two verses without the "additions":
"Ye call me Master and Lord: and ye say well; I AM" [in the Greek, εἰμί (eimi); in the Hebrew, יְהֹוָה (Yĕhovah) or LORD]!
"If I then, Lord and Master, have washed your feet; ye also ought to wash one another's feet."
Many of you may not see the difference as significant, but I assure you, there is a great difference. "I AM" is the name of the one true God: "And God said unto Moses, I AM THAT I AM: and He said, Thus shalt thou say unto the children of Israel, I AM hath sent me unto you" (Ex. 3:14). Like the ten other times in the Gospel of John, Jesus was declaring Himself to be the "I AM" of Scripture (Jn. 6:35; 8:12; 8:58; 10:7; 10:11; 10:36; 11:25; 14:6; 15:1; 18:6).
Jesus is not our Master and Lord; He is THE Master and Lord!