Ezekiel 4:12

And thou shalt eat it [as] barley cakes
That is, the bread made of wheat, barley, beans, lentiles, millet, and fitches, was to be made in the form of barley cakes, and to be baked as they; not in an oven, but under ashes; and these ashes not of wood, or straw, or turf, but as follows: and thou shalt bake it with dung that cometh out of men, in their
sight:
the prophet was to take human dung, and dry it, and then cover the cakes or loaves of his mixed bread with it, and burn it over them, and with it bake it; which must be a very disagreeable task to him, and make the food very nauseous, both to himself and to the Jews, in whose sight it was done; and this shows scarcity of fuel, and the severity of the famine; that they had not fuel to bake with, or could not stay till it was baked in an oven, and therefore took this method; as well as points at what they were to eat when carried captive, as follows: