What is the manna mentioned in the bible—animal, vegetable, or mineral??
In brief, all three: the substance called manna is the result of a insect-plant collaboration, and it’s possible the substance has mineral content. In Exodus Chapter 16, while the Israelites are traversing the desert after fleeing Egypt, God speaks to Moses of a substance that is revealed after the morning dew evaporates: “a fine, scale-like thing, fine as the hoar-frost on the ground” which is to be consumed like bread. The Israelites called it man (derived from the word ‘what,’ or ‘what is it’), “and it was like coriander seed, white; and the taste of it was like wafers made with honey.” According to the text, the manna sustained them for their forty years of dwelling in the desert. In Numbers Chapter 11, manna resembles coriander seed but also bdellium [b’dolach], which may or may not refer to an aromatic resin emitted by Commiphora [myrrh tree]. “The people went about, and gathered it, and ground it in mills, or beat it in mortars, and seethed it in pots, and made cakes of it; and the taste of it was as the taste of a cake baked with oil.”
Theories of manna’s identity have ranged from the improbable—a type of lichen not found in the Sinai Desert—to the plausible: a sweet exudation from a plant, caused by scale insects or aphids feeding on it. Possible plant sources include Anabasis setifera, Gomphocarpus sinaicus, Tamarix nilotica, Acacia raddiana, Capparis cartilaginea and C. spinosa v. aravensis, Pyrethrum santolinoides, and especially Haloxylon salicornicum, which grows commonly in the southern Sinai. The latter plant is called ‘man rimth’ by Bedouins, who collect the sweet resin from the stems in summer. According to Israeli botanist Avinoam Danin, Haloxylon (formerly called Hammada) is probably the most plentiful source of this sweet substance, but other less common plants in the Sinai may also be sources. Therefore, manna refers to the sweet white substance exuded by some or all of these plants.
The term manna has since been used in other parts of the world to refer to any sweet substance exuding from plants. In Northern Iraq, the sweet substance, possibly caused by insects feeding on the plants, is harvested from ash trees [Fraxinus ornus]. According to the authors of “Identification of Sugars in the Manna of Northern Iraq,” the substance “usually accumulates on the leaves until they fall to the ground. The sugars are extracted from the raw material with boiling water and mixed with eggs to make a popular dessert.” The nougat-like treat is called mann al-sama (manna of the heavens). There is a similar sweet in Iran called gaz, made with honeydew or resin from plants like Tamarix gallica and Astragalus adscendens. Plants upon which psyllid insects have been feeding exude this substance. The insects place their eggs “alongside the main vein of fully-grown leaves, which then curl up around the vein. The nymphs begin feeding inside the rolled-up leaves before they are scattered over the plant during flowering. They can be seen between the sepals and petals, but not inside the corolla. The white, sticky, segmented strings of gaz are mostly secreted in the last instar stage. The segments indicate multiple excretions. The soft exudates harden, eventually detach from the nymph’s body, and remain in the foliage, mixed with the nymphs and often with the plant debris as well.”
Ancient Greek scholar Pliny the Elder, describes manna in his Natural History: “Honey comes out of the air, and is chiefly formed at the rising of the stars, and especially when the Dogstar itself shines forth […] at early dawn the leaves of trees are found bedewed with honey, and any persons who have been out under the morning sky feel their clothes smeared with damp and their hair stuck together, whether this is the perspiration of the sky or a sort of saliva of the stars or the moisture of the air purging itself.” According to Edward Parker in his book Ash (Reaktion Books, 2021), Greco-Roman tradition called the exudate from ash trees manna, and the practice of giving it to infants as a first food spread to Europe.
Sicily also has a long history of extracting manna from ash trees [Fraxinus ornus and F. angustifolia, primarily] for edible, medicinal, and cosmetic uses. There are ash plantations in the towns of Castelbuono, Pollina, and Cefalu. The tree bark is scored with a knife to harvest the liquid exudate, usually in summer to early autumn. The liquid solidifies rapidly when exposed to hot sun.