ישעיהו לב:א פירוש: רש״י ואבן עזרא

Behold, for righteousness shall a king reign Behold a king has no right to reign except to execute righteous judgment.

Behold a king shall reign, etc. This refers to Hezekiah and his princes, the firm establishment of whose government is promised.

and over princes who rule with justice And over whom should he reign? Over princes who rule with justice. The prophet says this concerning Ahaz, who was a wicked man, but Hezekiah his son shall rule, and he is worthy. ([Manuscripts read:] And he is worthy of reigning.)