They were all ashamed; rather, all are ashamed. The reference is not to the ambassadors, who felt no shame in their embassy, and probably returned elated by the promises made them; but to the subsequent feelings of the Jewish nation, when it was discovered by sad experience that no reliance was to be placed on "the strength of Pharaoh."
A people that could not profit them. Mr. Cheyne compares, very pertinently, an inscription of Sargon's, where he says of the people of Philistia, Judah, Edom, and Moab, that "they and their evil chiefs, to fight against me, unto Pharaoh, King of Egypt, a monarch who could not save them, their presents carried, and besought his alliance".
Egypt was, in fact, quite unable to cope with Assyria, and knew it. A shame, and also a reproach. A matter of which they would themselves be "ashamed," and with which the Assyrians would "reproach" them (as they did, 2 Kings 18:21, 2 Kings 18:24).