No one considers,
nor is there knowledge or discernment to say, Half of it I burned in the fire;
I also baked bread on its coals;
I roasted meat and have eaten.
And shall I make the rest of it an abomination?
Shall I fall down before a block of wood?
This flows from the preceding verse. That is, “no one considers” because the Lord has blinded them into their follies. Again, it should be obvious, the absurdity of idolatry, and the prophet criticizes them subtly as he emphasizes the fact that they do not notice that their gods were first used for a fire, burned to ashes in minutes. It was used by them, for them: for fire, baking, roasting. Half of it, anyway. But the other half (and here comes the insanity): an abomination, worship—before a block of wood! Oswalt has a wonderful discussion of the use of “abomination” to describe this act of worship before a block of wood:
This extreme conclusion is an important one. Why, if it is not a god, is it an abomination? Why not merely a mistake? It is because of what the worshiper has claimed for the block of wood. We have claimed that we can find the transcendent (the holy), the destiny and meaning of life, in the shapes and stuff of this world. But what if we are wrong? The consequences are of an ultimate nature. Thus an instructor might say to any unroped climber who reaches for an outcropping of rotten granite, “Death is in your hand.” A wrong choice is not merely a mistake when one’s whole life rides on it (The Book of Isaiah, chapters 40-66, 185).