This broken reed; rather, as in 2 Kings 18:21, this bruised reed (comp. Isaiah 42:3). A reed may be "bruised," and wholly untrustworthy as a support, while it appears sound. A "broken" reed no one would lean on.
Egypt. There had been times when Egypt was a strong power, feared and respected by her neighbours, and a terror even to Assyria. But these times were long past. For the last fifty years the country had been divided against itself (see the comment on Isaiah 19:2), split up into a number of petty principalities, Recently the neighbouring kingdom of Ethiopia had claimed and exercised a species of sovereignty over the entire Nile valley, while allowing tributary princes to govern different portions of it.
Of these princes the most important at the time of Rabshakeh's embassy seems to have been Shabatok, who reigned in Memphis, probably from b.c. 712 to b.c. 698. Egypt is likened to a "bruised reed" on account of her untrustworthincss.
"So" (Sabaco) had given no substantial help to Hashes. Shabatok was little likely to imperil himself in order to assist Hezekiah. Even Tirhakah would probably avoid, as long as he could, a conflict with the full power of Assyria.
Pharaoh, King of Egypt. Sennacherib uses the generic term, "Pharaoh," instead of mentioning any of the petty princes by name, because he means to speak generally. The King of Egypt, under present circumstances, whoever he may be, is no better than a bruised reed.
In his own inscriptions, Sennacherib about this time uses the expression, "the kings of Egypt".