Isaiah 35:10

Language: literally, applying to the return from Babylon; figuratively and more fully to the completed redemption of both literal and spiritual Israel. joy upon . . . heads-- (Psa 126:2). Joy manifested in their countenances. Some fancy an allusion to the custom of pouring oil "upon the head," or wearing chaplets in times of public festivity (Ecc 9:8). This and the thirty-seventh through thirty-ninth chapters form the historical appendix closing the first division of Isaiah's prophecies, and were added to make the parts of these referring to Assyria more intelligible. So Jer. 52:1-34; compare 2Ki. 25:1-30. The section occurs almost word for word (Kg2 18:13, Kg2 18:17-20; 2Ki. 19:1-37); Kg2 18:14-16, however, is additional matter. Hezekiah's "writing" also is in Isaiah, not in Kings (Isa 38:9-20). We know from Ch2 32:32 that Isaiah wrote the acts of Hezekiah. It is, therefore, probable, that his record here (Isa. 36:1-39:8) was incorporated into the Book of Kings by its compiler. Sennacherib lived, according to Assyrian inscriptions, more than twenty years after his invasion; but as Isaiah survived Hezekiah (Ch2 32:32), who lived upwards of fifteen years after the invasion (Isa 38:5), the record of Sennacherib's death (Isa 37:38) is no objection to this section having come from Isaiah; 2Ch. 32:1-33 is probably an abstract drawn from Isaiah's account, as the chronicler himself implies (Ch2 32:32).

— Jamieson-Fausset-Brown Commentary (public domain)