The name “God of your father David” was spoken to two kings of Judah. The prophet Elijah sent a letter from God to warn King Jehoram that God was about to punish the king for his evil. In a second incident, Isaiah delivered a message to King Hezekiah that included the same name for God.
All the kings of Judah were descended from King David; in a sense, David was the father of them all.
God of your father David in Hebrew:
’Elohei Dawid ’avikha
Strong’s Concordance numbers: 430, 1732, 1
Bible references: 2 Kings 20:5; 2 Chron. 21:12; Isa. 38:5
“Go back and tell Hezekiah, the ruler of my people, ‘This is what the Lord, the God of your father David, says: I have heard your prayer and seen your tears; I will heal you. On the third day from now you will go up to the temple of the Lord.’” (2 Kings 20:5 NIV)
Elsewhere a similar name of God appears: LORD God of David.