John 13:13 - Ellicott's Commentary On The Whole Bible

Ye call me Master and Lord — i.e., Master in the sense of Teacher. The word in the original is not “Rabbi.” (Comp. Note on John 11:28.) The Jewish pupils called their teachers “Rabbi” and “Mar” (Teacher), and it was not permitted to any pupil to call his teacher by his proper name (Sanhedr., fol. 100, §1). The word “Master” here refers to His position as their Teacher; the word Lord to the reverence which they paid to Him. These were the common titles of everyday life which He here asserts for Himself.