A.T. Robertson Commentary Mark 12:6

"He had yet one, a beloved son: he sent him last unto them, saying, They will reverence my son." — Mark 12:6 (ASV)

A beloved son (υιον αγαπητον). Luke 20:13 has τον υιον τον αγαπητον. Jesus evidently has in mind the language of the Father to him at his baptism (Matthew 3:17; Luke 3:22).

Last (εσχατον). Only in Mark. See on Mt 21:37 for discussion of "reverence."