Jesus called their attention to David in Psalm
110 in regards to the Messiah, "The Lord said
unto my Lord, Sit thou at my right hand, until
I make thine enemies thy footstool."

Why did David call Him Lord, if He were his son?
Would Abraham call his sons Isaac, Jacob or
Joseph, Lord? Why did David?

There can be only one explanation. The Messiah
had human nature through His mother, that way
was He David's son, but He was of the Father in
heaven.