12 And when he was in distress, he besought Jehovah his God, and humbled himself greatly before the God of his fathers. 13 And he prayed unto him; and he was entreated of him, and heard his supplication, and brought him again to Jerusalem into his kingdom. Then Manasseh knew that Jehovah he was God. 14 Now after this he built an outer wall to the city of David, on the west side of Gihon, in the valley, even to the entrance at the fish gate; and he compassed Ophel about [with it], and raised it up to a very great height: and he put valiant captains in all the fortified cities of Judah. 15 And he took away the foreign gods, and the idol out of the house of Jehovah, and all the altars that he had built in the mount of the house of Jehovah, and in Jerusalem, and cast them out of the city. 16 And he built up the altar of Jehovah, and offered thereon sacrifices of peace-offerings and of thanksgiving, and commanded Judah to serve Jehovah, the God of Israel. 17 Nevertheless the people sacrificed still in the high places, but only unto Jehovah their God. 18 Now the rest of the acts of Manasseh, and his prayer unto his God, and the words of the seers that spake to him in the name of Jehovah, the God of Israel, behold, they are written among the acts of the kings of Israel. 19 His prayer also, and how [God] was entreated of him, and all his sin and his trespass, and the places wherein he built high places, and set up the Asherim and the graven images, before he humbled himself: behold, they are written in the history of Hozai. 20 So Manasseh slept with his fathers, and they buried him in his own house: and Amon his son reigned in his stead.

Matthew Henry's Commentary on 2 Chronicles 33:12-20

Commentary on 2 Chronicles 33:1-20

(Read 2 Chronicles 33:1-20)

We have seen Manasseh's wickedness; here we have his repentance, and a memorable instance it is of the riches of God's pardoning mercy, and the power of his renewing grace. Deprived of his liberty, separated from his evil counsellors and companions, without any prospect but of ending his days in a wretched prison, Manasseh thought upon what had passed; he began to cry for mercy and deliverance. He confessed his sins, condemned himself, was humbled before God, loathing himself as a monster of impiety and wickedness. Yet he hoped to be pardoned through the abundant mercy of the Lord. Then Manasseh knew that Jehovah was God, able to deliver. He knew him as a God of salvation; he learned to fear, trust in, love, and obey him. From this time he bore a new character, and walked in newness of life. Who can tell what tortures of conscience, what pangs of grief, what fears of wrath, what agonizing remorse he endured, when he looked back on his many years of apostacy and rebellion against God; on his having led thousands into sin and perdition; and on his blood-guiltiness in the persecution of a number of God's children? And who can complain that the way of heaven is blocked up, when he sees such a sinner enter? Say the worst against thyself, here is one as bad who finds the way to repentance. Deny not to thyself that which God hath not denied to thee; it is not thy sin, but thy impenitence, that bars heaven against thee.