Isaiah 36:6

He knew that some of the Judean nobles had put their trust in Egypt and had sent ambassadors there to make a treaty (cf. Isaiah 30:1-7). But he also knew, better than those officials, that Egypt was not only an unreliable ally but a dangerous one, an opinion Isaiah shared (cf. ch. 20; Isaiah 28:15; Ezekiel 29:6). Sennacherib had already defeated the Egyptians, who for the first and last time had unsuccessfully come to the aid of the Philistines, at Eltekeh northwest of Lachish.