1 Manasseh was twelve years old when he began to reign, and reigned fifty and five years in Jerusalem. And his mother's name was Hephzi-bah. 2 And he did that which was evil in the sight of the LORD, after the abominations of the heathen, whom the LORD cast out before the children of Israel. 3 For he built up again the high places which Hezekiah his father had destroyed; and he reared up altars for Baal, and made a grove, as did Ahab king of Israel; and worshipped all the host of heaven, and served them. 4 And he built altars in the house of the LORD, of which the LORD said, In Jerusalem will I put my name. 5 And he built altars for all the host of heaven in the two courts of the house of the LORD. 6 And he made his son pass through the fire, and observed times, and used enchantments, and dealt with familiar spirits and wizards: he wrought much wickedness in the sight of the LORD, to provoke him to anger. 7 And he set a graven image of the grove that he had made in the house, of which the LORD said to David, and to Solomon his son, In this house, and in Jerusalem, which I have chosen out of all tribes of Israel, will I put my name for ever: 8 Neither will I make the feet of Israel move any more out of the land which I gave their fathers; only if they will observe to do according to all that I have commanded them, and according to all the law that my servant Moses commanded them. 9 But they hearkened not: and Manasseh seduced them to do more evil than did the nations whom the LORD destroyed before the children of Israel. 10 And the LORD spake by his servants the prophets, saying, 11 Because Manasseh king of Judah hath done these abominations, and hath done wickedly above all that the Amorites did, which were before him, and hath made Judah also to sin with his idols: 12 Therefore thus saith the LORD God of Israel, Behold, I am bringing such evil upon Jerusalem and Judah, that whosoever heareth of it, both his ears shall tingle. 13 And I will stretch over Jerusalem the line of Samaria, and the plummet of the house of Ahab: and I will wipe Jerusalem as a man wipeth a dish, wiping it, and turning it upside down. 14 And I will forsake the remnant of mine inheritance, and deliver them into the hand of their enemies; and they shall become a prey and a spoil to all their enemies; 15 Because they have done that which was evil in my sight,and have provoked me to anger, since the day their fathers came forth out of Egypt, even unto this day. 16 Moreover Manasseh shed innocent blood very much, till he had filled Jerusalem from one end to another; beside his sin wherewith he made Judah to sin, in doing that which was evil in the sight of the LORD. 17 Now the rest of the acts of Manasseh, and all that he did, and his sin that he sinned, are they not written in the book of the chronicles of the kings of Judah? 18 And Manasseh slept with his fathers, and was buried in the garden of his own house, in the garden of Uzza: and Amon his son reigned in his stead. 19 Amon was twenty and two years old when he began to reign, and he reigned two years in Jerusalem. And his mother's name was Meshullemeth, the daughter of Haruz of Jotbah. 20 And he did that which was evil in the sight of the LORD, as his father Manasseh did. 21 And he walked in all the way that his father walked in, and served the idols that his father served, and worshipped them: 22 And he forsook the LORD God of his fathers, and walked not in the way of the LORD. 23 And the servants of Amon conspired against him, and slew the king in his own house. 24 And the people of the land slew all them that had conspired against king Amon; and the people of the land made Josiah his son king in his stead. 25 Now the rest of the acts of Amon which he did, are they not written in the book of the chronicles of the kings of Judah? 26 And he was buried in his sepulchre in the garden of Uzza: and Josiah his son reigned in his stead.
[AD 380] Apostolic Constitutions on 2 Kings 21:1-17
For it is written thus in the fourth book of Kings and the second book of Chronicles, or of Days: “Manasseh was twelve years old when he began to reign; he reigned fifty-five years in Jerusalem. His mother’s name was Hephzibah. He did what was evil in the sight of the Lord, following the abominable practices of the nations that the Lord drove out before the people of Israel. For he rebuilt the high places that his father Hezekiah had destroyed; he erected altars for Baal, made a sacred pole, as King Ahab of Israel had done, worshiped all the host of heaven and served them. He built altars in the house of the Lord, of which the Lord had said, ‘In Jerusalem I will put my name.’ He built altars for all the host of heaven in the two courts of the house of the Lord.” And Manasseh raised altars and served Baal there and said, “My name will last forever.” “He built altars for all the host of heaven in the two courts of the house of the Lord. He made his son pass through fire; he practiced soothsaying and augury and dealt with mediums and with wizards. He did much evil in the sight of the Lord, provoking him to anger. The carved image of Asherah that he had made he set in the house of which the Lord said to David and to his son Solomon, ‘In this house and in Jerusalem, which I have chosen out of all the tribes of Israel, I will put my name forever; I will not cause the feet of Israel to wander any more out of the land that I gave to their ancestors, if only they will be careful to do according to all that I have commanded them and according to all the law that my servant Moses commanded them.’ ” But they did not listen; Manasseh misled them to do more evil than the nations had done that the Lord destroyed before the people of Israel.The Lord said by his servants the prophets, “Because King Manasseh of Judah has committed these abominations, has done things more wicked than all that the Amorites did, who were before him, and has caused Judah also to sin with his idols; therefore thus says the Lord, the God of Israel, I am bringing on Jerusalem and Judah such evil that the ears of everyone who hears of it will tingle. I will stretch over Jerusalem the measuring line for Samaria and the plumb line for the house of Ahab; I will wipe Jerusalem as one wipes a dish, wiping it and turning it upside down. I will cast off the remnant of my heritage and give them into the hand of their enemies; they shall become a prey and a spoil to all their enemies, because they have done what is evil in my sight and have provoked me to anger, since the day their ancestors came out of Egypt, even to this day.” Moreover Manasseh shed very much innocent blood, until he had filled Jerusalem from one end to another, besides the sin that he caused Judah to sin so that they did what was evil in the sight of the Lord.” “Therefore the Lord brought against them the commanders of the army of the king of Assyria, who took Manasseh captive in manacles, bound him with fetters and brought him to Babylon.” And he was bound and shackled all over with iron in the house of the prison. And bread made of bran was given to him scantly and by weight, and water mixed with vinegar but a little and by measure, so much as would keep him alive; and he was in straits and sore afflictions. “While he was in distress he entreated the favor of the Lord his God and humbled himself greatly before the God of his ancestors. He prayed to him,” saying, “O Lord, almighty God of our fathers Abraham, Isaac and Jacob and of their righteous seed, who have made heaven and earth, with all the ornaments thereof, who have bound the sea by the word of your commandment, who have shut up the deep and sealed it by your terrible and glorious name, whom all people fear and tremble before your power; for the majesty of your glory cannot be borne, and your angry threatening toward the sinner is insupportable. But your merciful promise is unmeasurable and unsearchable; for you are the most high Lord, of great compassion, long suffering, very merciful and who repents of the evils of humankind. You, O Lord, according to your great goodness, have promised repentance and forgiveness to them who have sinned against you, and of your infinite mercy you have appointed repentance to sinners, that they may be saved. You therefore, O Lord, that are the God of the just, have not appointed repentance to the just as to Abraham and Isaac and Jacob, who have not sinned against you; but you have appointed repentance to me that am a sinner: for I have sinned above the number of the sands of the sea. My transgressions, O Lord, are multiplied; my transgressions are multiplied, and I am not worthy to behold and see the height of heaven for the multitude of my iniquity. I am bowed down with many iron bands; for I have provoked your wrath and done evil before you, setting up abominations and multiplying offenses. Now, therefore, I bow the knee of my heart, beseeching you of grace. I have sinned, O Lord, I have sinned, and I acknowledge my iniquities; wherefore I humbly beseech you, forgive me, O Lord, forgive me, and do not destroy me with my iniquities. Be not angry with me forever, by reserving evil for me; neither condemn me into the lower part of the earth. For you are the God, even the God of them that repent, and in me you will show your goodness; for you will save me that am unworthy, according to your great mercy. Therefore I will praise you forever all the days of my life; for all the powers of the heavens do praise you, and yours is the glory forever and ever. Amen.”
“And God heard his plea” and had compassion on him. And there appeared a flame of fire about him, and all the iron shackles and chains that were about him fell off; and the Lord healed Manasseh from his affliction and “restored him again to Jerusalem and to his kingdom. Then Manasseh knew that the Lord indeed was God.” And he worshiped the Lord God alone with all his heart and with all his soul, and all the days of his life; and he was esteemed righteous. “He took away the foreign gods and the idol from the house of the Lord and all the altars that he had built on the mountain of the house of the Lord and in Jerusalem, and he threw them out of the city. He also restored the altar of the Lord and offered on it sacrifices of well-being and of thanksgiving; and he commanded Judah to serve the Lord the God of Israel.” … You have heard, our beloved children, how the Lord God for a while punished him who was addicted to idols and had slain many innocent persons; and yet that he received him when he repented, and forgave him his offenses and restored him to his kingdom. For he not only forgives the penitent, but also reinstates them in their former dignity.

[AD 407] John Chrysostom on 2 Kings 21:1-17
For so Manasseh had perpetrated innumerable pollutions, having both stretched out his hands against the saints, and brought abominations into the temple, and filled the city with murders and wrought many other things beyond excuse; yet nevertheless after so long and so great wickedness, he washed away from himself all these things. How and in what matter? By repentance and self-examination. For there is no sin that does not yield and give way to the power of repentance, or rather to the grace of Christ. Since if we would but only change, we have him to assist us. And if you are desirous to become good, there is none to hinder us; or rather there is one to hinder us, the devil, yet he has no power, so long as you choose what is best and so attract God to your aid.

[AD 1781] Richard Challoner on 2 Kings 21:6
Pythons: That is, diviners by spirits.
[AD 380] Apostolic Constitutions on 2 Kings 21:19-24
There is no sin more grievous than idolatry, for it is an impiety against God, and yet even this sin has been forgiven, on sincere repentance. But if anyone sins in direct opposition and on purpose to try whether God will punish the wicked or not, such a one shall have no remission, although he says to himself, “All is well, and I will walk according to the customs of my evil heart.” Such a one was Amon the son of Manasseh. For the Scripture says, “And Amon reasoned an evil reasoning of transgression and said, My father from his childhood was a great transgressor and repented in his old age; and now I will walk as my soul lusts, and afterwards I will return to the Lord.” And he did evil in the sight of the Lord above all who were before him. And the Lord God soon destroyed him utterly from his good land. And his servants conspired against him and killed him in his own house, and he reigned two years only.