Matthew 22:45

If David then call him Lord
That is, the Messiah, which is taken for granted, nor could the Pharisees deny it,

how is he his son?
The question is to be answered upon true and just notions of the Messiah, but unanswerable upon the principles of the Pharisees; who expected the Messiah only as a mere man, that should be of the seed of David, and so his son; and should sit upon his throne, and be a prosperous and victorious prince, and deliver them out of the hands of their temporal enemies: they were able to make answer to the question, separately considered, as that he should be of the lineage and house of David; should lineally descend from him, be of his family, one of his offspring and posterity, and so be properly and naturally his son; but how he could be so, consistent with his being David's Lord, puzzled them. Had they understood and owned the proper divinity of the Messiah, they might have answered, that as he was God, he was David's Lord, his maker, and his king; and, as man, was David's son, and so both his root and offspring; and this our Lord meant to bring them to a confession of, or put them to confusion and silence, which was the consequence.