"Go and tell Hezekiah that this is what the LORD, the God of your father David, says: 'I have heard your prayer; I have seen your tears. Behold, I will add fifteen years to your life.
Cross References
2 Kings 18:2He was twenty-five years old when he became king, and he reigned in Jerusalem twenty-nine years. His mother's name was Abi, the daughter of Zechariah.
2 Kings 18:13In the fourteenth year of Hezekiah's reign, Sennacherib king of Assyria attacked and captured all the fortified cities of Judah.
Isaiah 38:4And the word of the LORD came to Isaiah, saying,
 Treasury of Scripture
Go, and say to Hezekiah, Thus said the LORD, the God of David your father, I have heard your prayer, I have seen your tears: behold, I will add to your days fifteen years.
and say
2 Samuel 7:3-5
 And Nathan said to the king, Go, do all that is in thine heart; for the LORD is with thee… 
1 Chronicles 17:2-4
 Then Nathan said unto David, Do all that is in thine heart; for God is with thee… 
God
Isaiah 7:13,14
 And he said, Hear ye now, O house of David; Is it a small thing for you to weary men, but will ye weary my God also? … 
1 Kings 8:25
 Therefore now, LORD God of Israel, keep with thy servant David my father that thou promisedst him, saying, There shall not fail thee a man in my sight to sit on the throne of Israel; so that thy children take heed to their way, that they walk before me as thou hast walked before me.
1 Kings 9:4,5
 And if thou wilt walk before me, as David thy father walked, in integrity of heart, and in uprightness, to do according to all that I have commanded thee, and wilt keep my statutes and my judgments: … 
I have heard
2 Kings 19:20
 Then Isaiah the son of Amoz sent to Hezekiah, saying, Thus saith the LORD God of Israel, That which thou hast prayed to me against Sennacherib king of Assyria I have heard.
Psalm 34:5,6
 They looked unto him, and were lightened: and their faces were not ashamed… 
Luke 1:13
 But the angel said unto him, Fear not, Zacharias: for thy prayer is heard; and thy wife Elisabeth shall bear thee a son, and thou shalt call his name John.
I have seen
Psalm 39:12
 Hear my prayer, O LORD, and give ear unto my cry; hold not thy peace at my tears: for I am a stranger with thee, and a sojourner, as all my fathers were.
Psalm 56:8
 Thou tellest my wanderings: put thou my tears into thy bottle: are they not in thy book?
Psalm 147:3
 He healeth the broken in heart, and bindeth up their wounds.
I will
Job 14:5
 Seeing his days are determined, the number of his months are with thee, thou hast appointed his bounds that he cannot pass;
Psalm 116:15
 Precious in the sight of the LORD is the death of his saints.
Acts 27:24
 Saying, Fear not, Paul; thou must be brought before Caesar: and, lo, God hath given thee all them that sail with thee.