John Gill Reformed Baptist @doctorgill

Master, which is the great commandment in the law? He calls him "master, Rabbi, or doctor", as the Sadducees had in Mat 22:24 either because he was usually so called by his disciples, and by the generality of the people; or merely in complaisance to engage his attention to him, and his question: and might hereby suggest, that should he return a proper and satisfactory...

Albert Barnes Presbyterian @notesbybarnes

Verse 33. (h) "astonished at his doctrine"