This bruised reed - The “tall reed of the Nile bulrush” fitly symbolized the land where it grew. Apparently strong and firm, it was quite unworthy of trust. Let a man lean upon it, and the rotten support instantly gave way, wounding the hand that stayed itself so insecurely. So it was with Egypt throughout the whole period of Jewish history (compare 2 Kings 17:4-6). Her actual practice was to pretend friendship, to hold out hopes of support, and then to fail in time of need.
Related Commentaries of 2 Kings 18:21
2 Kings 18:21
21 Now, behold, thou trustesti upon the staff of this bruised reed, even upon Egypt, on which if a man lean, it will go into his hand, and pierce it: so is Pharaoh king of Egypt unto all that trust on him.