Why does it say "Hen l'Tzedek Yimlach Melech"?
Rashi: A king should rule only if he will do righteous judgment. The Navi discussed Achaz, who was a Rasha, but his son Chizkiyah is proper to rule.
Radak: Chizkiyah will rule to do Tzedek and Mishpat. Therefore, this salvation will be in his days.
Malbim: This is the merit of Chizkiyah. He did not reign for wars and to conquer nations, only for Tzedek and to oversee officers. Refer to 32:1:2:2.
What is the meaning of "ul'Sarim l'Mishpat Yashoru"?
Rashi: Who should rule? Officers who are straight for Mishpat. Radak - the prefix Lamed in ul'Sarim is extra, like "Hargu l'Avner" (Shmuel II, 3:30), "veha'Shelishi l'Avshalom" (Divrei ha'Yamim I, 3:2) and similar verses.
Malbim: The king must oversee officers, that they will conduct properly. Mishpat is letter of the law; Tzedek is based on the time and place, beyond the letter of the law. Only the king can do so.
