So, king of Egypt— This So seems to be the same as Sabachon, the AEthiopian king of Egypt, of whom Herodotus relates, that being warned in a dream, he departed of his own accord from Egypt, after he had reigned there fifteen years. In the beginning of Hezekiah's reign he invaded Egypt, and having taken Boccharis the king thereof prisoner, with great cruelty burned him alive, and then seized on his kingdom.
Related Commentaries of 2 Kings 17:4
2 Kings 17:4
4 And the king of Assyria found conspiracy in Hoshea: for he had sent messengers to So king of Egypt, and brought no presentb to the king of Assyria, as he had done year by year: therefore the king of Assyria shut him up, and bound him in prison.