Because he killed innocent people and stained Jerusalem with their blood, the Lord was unwilling to forgive them.

So this is what the Lord says about the king of Assyria: “He will not enter this city, nor will he shoot an arrow here. He will not attack it with his shield-carrying warriors, nor will he build siege works against it.

Furthermore Manasseh killed so many innocent people, he stained Jerusalem with their blood from end to end, in addition to encouraging Judah to sin by doing evil in the sight of the Lord.