Mark 12:35

And Jesus answered and said, while he taught in the temple, How say the scribes that Christ is the son of David?

And Jesus answered and said,.... To the Pharisees that were gathered together about him; See Gill on "Matthew 22:41".

while he taught in the temple; Whilst he was in the temple, and as he was teaching the people there; among other things in his doctrine, he put this question,

How say the scribes, that Christ is the son of David? Not that Christ meant to deny or invalidate the truth of this; for the Messiah was certainly to be the son of David, and was; but he wanted to know, inasmuch as they commonly said, and instructed the people to believe, and it was in general believed by them, that he was David's son, how they could reconcile this to his being the Lord of David: or how they could give out, that he was only and merely the Son of David, when he was David's Lord. Matthew relates the matter thus; that Christ first put these questions to them, what they thought of the Messiah, and whose son he was; and that they immediately replied, he was the son of David: wherefore this question seems to be put upon that, with another along with it,

how then doth David in spirit call him Lord?

See Gill on "Matthew 22:42",

See Gill on "Matthew 22:43".