Why would God's own word cause people to fall and be broken? This verse reveals a dangerous disconnect between hearing God's message and truly obeying it.
Isaiah 28:13 paints a picture of people who hear God's word, but not to understand or obey. The repetition of "precept upon precept, line upon line, here a little, there a little" wasn't meant to be a gentle, drawn-out lesson for children. Instead, the people of Judah were mocking these simple instructions, treating them with contempt.
God’s response? He would give them exactly what they were mockingly asking for: more of the same simple, repetitive message. But the purpose would change. Instead of leading them to wisdom, this constant barrage of God's word, delivered through judgment and consequence, would become the very thing causing them to "fall backward, and be broken, and snared, and taken."
Their scorn turned God's intended blessing of instruction into a curse of judgment. They were given enough of God's word to condemn them, to make their falling inevitable.