What does Matthew 22:44 mean?

Jesus has asked the Pharisees a challenging question of His own: whose son is the Christ? Christ is from the Greek word Christos, a translation of the Hebrew word Mashiyach, meaning "Messiah." They have answered, rightly, that the Christ is the descendant of David (Matthew 22:41–43). Jesus does not correct them (Matthew 1:1,17), but He does challenge the implications of their answer.

Nearly everyone agreed that Psalm 110, written by David, was about the Messiah. In the first verse of that Psalm, King David calls the Christ "Lord." Now Jesus quotes the verse to show what He means (Psalm 110:1). Breaking it down, David writes that "the Lord" [God] said to [David's] Lord [Christ] to sit at [God's] right hand [the place of greatest honor]. Jesus is asking why David would call his "son," meaning his own descendant, "my Lord" who sits at the right hand of God unless the Christ has some significant status beyond being David's son.

This Old Testament reference is mentioned many other times in the New Testament, and for good reason (Acts 2:34; 1 Corinthians 15:25; Hebrews 1:13; 10:13). The divine status of the Messiah is a clear teaching of the Old Testament.