Isaiah 38:4-5

God sent His answer to Hezekiah’s prayer back to him through Isaiah (cf. 2 Kings 20:4). The Lord identified Himself as the God of David, his forefather. Perhaps the reference to David helped Hezekiah remember God’s promises to David about the perpetuity of his dynasty (2 Samuel 7). This reminded the king that God would remain faithful and care for His people.

God had noted Hezekiah’s prayer and his tears, and they had touched Him. The Lord graciously promised him 15 more years of life. Long life was a blessing that God had promised the godly under the Old Covenant, so His grace was in harmony with His promises.