Charles Ellicott Commentary John 1:38

"And Jesus turned, and beheld them following, and saith unto them, What seek ye? And they said unto him, Rabbi (which is to say, being interpreted, Teacher), where abideth thou?" — John 1:38 (ASV)

Jesus turned, and saw them following.—They follow wishing, and yet not daring, to question Him. He sees this and seeks to draw them out by asking the first question Himself. They are not prepared for this question and wish for more than a passing interview. They inquire, “Where do you sojourn?” “Where are you staying for the night?” They will visit Him and ask the many things they seek.

They address Him as “Rabbi,” placing themselves in the position of His scholars; but they have not yet learned all that John had taught them about His office. This title was natural for them, as it was the then-current title of a revered teacher, and one that John’s disciples applied to him (John 3:26). But the writer remembers it was a modern word , known to Jews only since the days of Hillel (president of the Sanhedrin around 30 BC), not likely to be known to Greeks at all, and he therefore translates it, just as he does with Messias and Cephas in this same section.