How can David call God his Lord, if He was David's son?
The passage that you refer to is,
Now while the Pharisees were gathered together, Jesus asked them a question: “What do you think about the Christ, whose son is He?” They said to Him, “The son of David.” He said to them, “Then how does David in the Spirit call Him ‘Lord,’ saying, ‘THE LORD SAID TO MY LORD, “SIT AT MY RIGHT HAND, UNTIL I PUT YOUR ENEMIES BENEATH YOUR FEET”‘? “If David then calls Him ‘Lord,’ how is He his son?” No one was able to answer Him a word, nor did anyone dare from that day on to ask Him another question. (NAS95S) Matt 22.41-46
The gospel of Matthew reveals that Jesus had asked the Pharisees who was the ancestorial father of the Messiah. While there were many ancestorial fathers that they could have named, there was only one that was important to the Jews, and the Pharisees had the answer correct. The Messiah was to be a descendant of King David. Then Jesus asks a difficult question, “How does David call . . . Him Lord?” and then He quotes Psalm 110:1. The first “LORD” in Psalm 110 is translated from the Hebrew word Yahweh or Jehovah. It refers to God the Father. The second “Lord” is the translation of the Hebrew word “Adonai” which means simply Lord but can also refer to God.
Who was Adonai? The Pharisees did not want to explain. Today however, Jewish rabbis claim that Adonai refers to the “king.” But this does not make sense since King David wrote the Psalm. There was no other king in Israel. This means that King David called someone else his Lord. He was referring to God. In Psalm 110:1 Adonai referred to the Messiah since the rest of Psalms indicates that all the enemies of Israel would serve Him or be in submission to Him. The Jews of Jesus’ time understood this to be a reference to the Messiah. King David was referring to Adonai as his own Lord. How can one of David’s descendants be his Lord? There is only one explanation as to how Adonai could be David’s son and also superior to David. The Messiah was and is also God.
All of the ancient prophecies pointed to Jesus Christ as the Messiah. Jesus was and is the long-awaited Jewish Messiah. He was a descendant of King David (Ps. 110:1; Jer. 23:5: Matthew 1:1-16; Luke 3:23-31). He was born in Bethlehem (Micah 5:2; Matthew 2:1-6; Luke 2:4-6). A crowd listening to Jesus in John 7 summarized the Jewish expectation well,
Has not the Scripture said that the Christ comes from the descendants of David, and from Bethlehem, the village where David was? (NAS95S) John 7:42
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