manna: [OE] Manna was introduced into Old English by Latin, which got it from Aramaic mannā. This was a derivative of Hebrew mān, one of a family of Semitic words denoting an edible substance exuded by a sort of tamarisk tree that grows in the Sinai desert. [manna etymology, manna origin, 英语词源]
Old English borrowing from Late Latin manna, from Greek manna, from Hebrew man, probably literally "substance exuded by the tamarisk tree," but used in Greek and Latin specifically with reference to the substance miraculously supplied to the Children of Israel during their wandering in the Wilderness (Ex. xvi:15). Meaning "spiritual nourishment" is attested from late 14c. Generalized sense of "something provided unexpectedly" is from 1590s.