Isaiah 37:9
"And he heard say concerning Tirhakah king of Ethiopia, He is come forth to make war with thee. And when he heard it, he sent messengers to Hezekiah, saying,"
Cross References (ranked by relevance)
Isaiah 18:1
Woe to the land shadowing with wings, which is beyond the rivers of Ethiopia:
Isaiah 20:5
And they shall be afraid and ashamed of Ethiopia their expectation, and of Egypt their glory.
Isaiah 37:7
Behold, I will send a blast upon him, and he shall hear a rumour, and return to his own land; and I will cause him to fall by the sword in his own land.