30:21 arm. Pharaoh Hophra had sent an army to the assistance of Zedekiah, but it was repulsed (Jer. 37:1–10; cf. Ezek. 17:15–17; 29:6, 7). The “arm” is a figure for military power. The exiles living in Babylon and the people in Jerusalem had hoped that Pharaoh would defeat Babylon, but this prophecy denies them. Instead, Babylon will break the arm of Pharaoh, leaving him unable to handle a sword, and useless as an ally for Israel.