Matthew Poole and continuators on Ezekiel 4:12

12 And thou shalt eat it as barley cakes, and thou shalt bake it with dung that cometh out of man in their sight.

These were delicacies with them when they could temper and make them right, but now these pitiful things should be to these half starved bodies as delicates. Or, rather because they were greedy, could not stay till they were baked. Or, least any should take it from them. Or, because they never had enough to make a loaf with, they eat them as Barley Cakes.

There would be no wood left for such necessary uses, nor yet dung of other Creatures, they would be all consumed by the length of the Seige too, what loathsome food was this, yet in this streitness of the Siege they are brought to it.

Openly that any might see it, from this passage some conclude this was actually done, and not only represented in a vision.