And when {e} he heard say of Tirhakah king of Ethiopia, {f} Behold, he is come out to fight against thee: he sent messengers again unto Hezekiah, saying,

(e) That is, Sennacherib.

(f) For the kings of Ethiopia and Egypt joined together against the king of Assyria because of his oppression of other countries.

Jamieson-Fausset-Brown Bible Commentary

9-13. when he heard say of Tirhakah ., Behold, he is come out to fight against thee, &c.-This was the "rumor" to which Isaiah referred [2Ki 19:7]. Tirhakah reigned in Upper Egypt, while So (or Sabaco) ruled in Lower Egypt. He was a powerful monarch, another Sesostris, and both he and Sabaco have left many monuments of their greatness. The name and figure of Tirhakah receiving war captives, are still seen in the Egyptian temple of Medinet Abou. This was the expected succor which was sneered at by Rab-shakeh as "a bruised reed" (2Ki 18:21). Rage against Hezekiah for allying himself with Egypt, or the hope of being better able to meet this attack from the south, induced him, after hearing the rumor of Tirhakah's advance, to send a menacing letter to Hezekiah, in order that he might force the king of Judah to an immediate surrender of his capital. This letter, couched in the same vaunting and imperious style as the speech of Rab-shakeh, exceeded it in blasphemy, and contained a larger enumeration of conquered places, with the view of terrifying Hezekiah and showing him the utter hopelessness of all attempts at resistance.

Matthew Henry's Concise Commentary

19:8-19 Prayer is the never-failing resource of the tempted Christian, whether struggling with outward difficulties or inward foes. At the mercy-seat of his almighty Friend he opens his heart, spreads his case, like Hezekiah, and makes his appeal. When he can discern that the glory of God is engaged on his side, faith gains the victory, and he rejoices that he shall never be moved. The best pleas in prayer are taken from God's honour.