Reference for Isaiah 14:30

for from the North smoke has come Retribution harsh as smoke shall come upon them from the north. Gaza and its boundaries, which Hezekiah smote, were in the south of Eretz Israel in the southwestern corner. Eretz Israel is found to be north of it. And so we find in Sifrei in Ha’azinu 322: They attempted to flee through the south, and they turned them over, as it is stated (Amos 1:6): “For three transgressions of Gaza... [because of their exiling a complete exile to deliver to Edom.]” Hence, we learn that Gaza is on the south.