The enormities of Manasseh were the climax in Judah’s long course of evil. The cup of iniquity was full and judgment was ready to fall. The good reign of Josiah brought a suspension for a time, not a revocation of the sentence of doom. The point had been reached where God refused to pardon the national guilt. But national must always be distinguished from personal guilt (see on ch. 17:20).
Innocent blood.
Including that of Isaiah (PK 382). Isaiah certainly would not have looked upon the abominations of Manasseh in silence and complacency, but would surely have lifted up his voice in stern rebuke against the misdeeds of the king.