«For David himself, inspired by the Holy Spirit declared: ‘The Lord said to my Lord: sit at my right until I put your enemies under your feet’. If David himself calls him Lord, in what way can he be his son?».
Today Jesus is remembering some prophetic words that King David had said 1,000 years before. The scene is very solemn: Jesus Christ applies to himself the title of "Son of David". The Jews knew that the Savior would be a descendant of David. But in Jesus there is much more: He is, above all, the Son of God, who is eternally with the Father.
—It is true that St. Joseph and the Virgin Mary were descending from David. But Mary is "the Virgin" because the One who begot Jesus in her womb was the Holy Spirit. And, because He comes from the Father, Jesus is the "true David" who can lead us to heaven. Such are the ways of God!