Ellicott's Commentary On The Whole Bible
Exodus 16:14
Was gone up — i.e., was drawn up by the heat of the sun.
A small round thing, as small as the hoar frost. — What the manna was has been much disputed. There are two natural substances, quite distinct, with which it has been compared, and by some persons identified. One is a deposit from the air, which falls indifferently on trees, stones, grass, &c, and is generally thick and sticky, like honey, but under certain circumstances is “concreted into small granular masses.” This bas been described by Aristotle (Hist. An., v. 22), Pliny (H. N., xi. 12), Avicenna(p. 212), Ǽlian (Hist. An., xv. 7), Shaw, Forskal, and others. It has been called ὰερόμελι or “air-honey” (Athen. Deipn, xi., p. 500). It is collected by the Arabs, and eaten with their unleavened cakes as a condiment. It so far resembles the manna that it comes with the dew, is spread upon the ground generally, and melts when the sun’s rays attain a certain power (Œdmann: Misc. Collect., vol. iv., p. 7). But it is never found in large quantities; it does not fall for more than two months in the year; and it is wholly unfit to serve as man’s principal food, being more like honey than anything else. The other substance is a gum which exudes from certain trees at certain seasons of the year, in consequence of the punctures made in their leaves by a small insect, the Coccus manniparus. It has been described at length by C. Niebuhr in his Description de l’ Arabie (pp. 128, 129); by Rauwolf (Travels, vol. I., p. 94); Gmelin (Travels through Russia to Persia, Part III., p. 28), and others. It is comparatively a dry substance, is readily shaken from the leaves, and consists of small yellowish – white grains, which are hard, and have been compared to coriander seed by moderns (Rauwolf, 50s.100). The name “manna” attaches in the East to this latter substance, which is employed both as a condiment, like the “air-honey,” and also as a laxative. The special points in which it differs from the manna of Scripture are its confinement to certain trees or bushes, its comparative permanency, for it “accumulates on the leaves” (Niebuhr, p. 129), and its unfitness for food. It has also, like the “air-honey,” only a short season — the months of July and August.
The manna of Scripture in certain respects resembles the one, and in certain other respects the other of these substances, but in its most important characteristics resembles neither, and is altogether sui generis. For (1) it was adapted to be men’s principal nourishment, and served the Israelites as such for forty years; (2) it was supplied in quantities far exceeding anything that is recorded of the natural substances compared with it; (3) it continued through the whole of the year; (4) for forty years it fell regularly for six nights following, and ceased upon the seventh night; (5) it “bred worms” if kept to a second day, when gathered on five days out of the six, but when gathered on the sixth day continued good throughout the seventh, and bred no worms. The manna of Scripture must therefore be regarded as a miraculous substance, created ad hoc, and not as a natural product. It pleased the Creator, however, to proceed on the lines of Nature, so to speak, and to assimilate His new to certain of His old creations.