from
Easton's 1897 Bible Dictionary
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; Isa. 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.