Dove’s dung

(2 Kings 6:25) has been generally understood literally

There are instances in history of the dung of pigeons being actually used as food during a famine. Compare also the language of Rabshakeh to the Jews (2 Kings 18:27; Isaiah 36:12). This name, however, is applied by the Arabs to different vegetable substances, and there is room for the opinion of those who think that some such substance is here referred to, as, e.g., the seeds of a kind of millet, or a very inferior kind of pulse, or the root of the ornithogalum, i.e., bird-milk, the star-of-Bethlehem.