The broken reed is one of the Old Testament’s more striking and memorable metaphors. I remember coming across it for the first time in the account of Assyria’s siege of Jerusalem during the reign of Hezekiah, which appears several times in the Old Testament, probably the lengthiest being in 2 Kings.
The backstory is this: The king of Assyria, the great world power of that day, had besieged and conquered Samaria, the capital of the northern kingdom. He carried away tens of thousands of Israelites captive, dispersing them throughout the cities of the Medes and the rest of his vast empire. Eight years later, when Sennacherib had received the Assyrian throne, he determined to finish the job begun by his predecessor.
Assyria set its sights on the southern kingdom of Judah.