Isaiah 37:8

“So Rabshakeh returned, &c.] To the king of Assyria his master, to give him an account how things went at Jerusalem, and that he could get no direct answer from the king of Judah, and to consult with him what was proper to be done in the present situation of things; leaving the army before Jerusalem, under the command of the other two generals. For that he should take the army with him does not seem reasonable, when Hezekiah and his people were in such a panic on account of it; besides, the king of Assyria’s letters to Hezekiah clearly suppose the army to be still at Jerusalem, or his menacing letters would have signified nothing; and after this the destruction of the Assyrian army before…”

“returned--to the camp of his master. Libnah--meaning "whiteness," the Blanche-garde of the Crusaders [STANLEY]. EUSEBIUS and JEROME place it more south, in the district of Eleutheropolis, ten miles northwest of Lachish, which Sennacherib had captured (see on Isa 36:2). Libnah was in Judea and given to the priests (Ch1 6:54, Ch1 6:57).”

“So Rabshakeh returned - Returned from Jerusalem to the camp of his master. He had received no answer to his insulting message Isaiah 36:21; he saw there was no prospect that the city would surrender; and he therefore returned again to the camp. And found the king of Assyria warring against Libnah - He had departed from Lachish. Why he had done this is unknown. It is possible that he had taken it, though this is not recorded anywhere in history. Or it is possible that he had found it impracticable to subdue it as speedily as he had desired; and had withdrawn from it for the purpose of subduing other places that would offer a more feeble resistance. Libnah was a city in the south of Judah…”

“37:8 Libnah was a city on the Philistine plain near Lachish. Sennacherib was preparing to fight both Egypt and Jerusalem when he sent word to Hezekiah.”

“Rabshakeh: Kg2 19:8, Kg2 19:9; Num 33:20, Num 33:21 Libnah: Jos 10:29, Jos 10:31-34, Jos 21:13; Kg2 8:22; Ch2 21:10 Lachish: Jos 12:11, Jos 15:39 Isaiah 37:9”

“Rabshakeh, who is mentioned alone in both texts as the leading person engaged, returns to Sennacherib, who is induced to make a second attempt to obtain possession of Jerusalem, as a position of great strength and decisive importance. "Rabshakeh thereupon returned, and found the king of Asshur warring against Libnah: for he had heard that he had withdrawn from Lachish. And he heard say concerning Tirhakah king of Ethiopia, (K. Behold), he has come out to make war with thee; and heard, and sent (K. and repeated, and sent) messengers to Hizkiyahu, saying." Tirhakah was cursorily referred to in Isa 18:1-7. The twenty-fifth dynasty of Manetho contained three Ethiopian rulers: Sabakon, Sebichōs…”