2 Kings 21:20
And he did that which was evil in the sight of the Lord, as his father Manasseh did.
Cross-reference
2 Kings 21:2–7
Parallel
2 Kings 21:2-7 details the specific evil deeds of Manasseh that Amon imitated, showing what 'evil' entailed.
2 Kings 3:2
Contrast
In 2 Kings 3:2, Jehoram does evil but not like his parents — contrasting Amon who matches his father's wickedness, highlighting his total corruption.
2 Chronicles 33:22
Parallel
2 Chronicles 33:22 confirms Amon's evil and adds that he worshiped the idols Manasseh made, expanding the parallel account.
2 Chronicles 33:23
Contrast
2 Chronicles 33:23 contrasts Amon with Manasseh: Manasseh humbled himself, but Amon did not, increasing his guilt.