מִכְתָּ֖ב לְחִזְקִיָּ֣הוּ מֶֽלֶךְ־יְהוּדָ֑ה בַּחֲלֹת֕וֹ וַיְחִ֖י מֵחָלְיֽוֹ׃
Rashi on Isaiah
The writing of Hezekiah Jonathan paraphrases: A writing of thanksgiving for the miracle performed for Hezekiah.
Ibn Ezra on Isaiah
ויחי And was recovered. Comp. עד חיותם till they were whole (Jos. 5:8), ואתה מחיה and thou preservest (Neh. 9:6). It might also mean, And he lived.1In this case the word מחליו which follows, must be translated: his illness being no more, or after having been ill.