My colleague Toby Sumpter points out that the series of judgments in Isaiah 9:8-21 is following a sacrificial sequence.

First, Yahweh threatens to break down the brick altars and sycamore shrines of Israel. They rebuild them, so He cuts them in pieces, like a sacrificial animal. They keep sinning, and so He lights a sacrificial fire that will burn them. The sacrifice ends with a macabre sacrificial meal, “each of them eats the flesh of his own arm” (v. 20).