All readers of the Scriptures remember the important part which manna played in the history of the Jews. The manna which is at the present day known in the Arabian desert through which the Israelites passed is collected in June from the tarfa or tamarisk shrub (Tamarix Gallica). According to Burkhardt, it drops from the thorns on to the sticks and leaves which cover the ground and must be gathered early in the day or it will be melted by the heat of the sun. Its fall is said to be caused by the punctures made by insects. The Arabs cleanse, boil and strain it and put it up in leather bottles, and thus prepared it will retain its virtues for several years. It is used in the place of honey or butter—it is never eaten alone. It is abundant only in wet seasons, and in a very dry year it is not found at all. It is not exactly peculiar in character, as there are several shrubs in India and Syria.
Salvadora—The arboreous Mustard Plant of Palestine.
Niebuhr discovered at Mardin, in Mesopotamia, on the leaves of a tree, a species of capparis, a kind of manna which appears during the months of July and August, being most plentiful in wet seasons. If shaken off before sunrise, it is pure white in color. If let remain, it collects until very thick, and the leaves are then gathered and steeped in boiling water until the manna floats to the top like oil. This is called by the natives manna essemma, heavenly manna.
Burkhardt found in the valley of Jordan a similar gum on the leaves and branches of the tree gharrob (a species of oak), which fell to the ground in drops of brown-gray dew. Its taste at first was sweet, but after a day's exposure to the elements became acrid.
The manna of European commerce is exported from Calabria and Sicily. It drops from punctures made in a species of ash by an insect resembling the locust. It is fluid at night, but begins to harden in the morning.
The manna of Scripture, which was the sole support of the Israelites for forty years, must be regarded as miraculous, as (1) manna is under ordinary circumstances stimulating rather than sustaining, (2) the season in which it is found does not extend over a term of more than three or four months, (3) it is found only in small quantities compared to the enormous amount—15,000,000 pounds a week—which would have been necessary to provide each member of the Israelite camp with the rations mentioned, (4) a double quantity certainly does not fall on the day preceding the Sabbath and (5) no natural product ceases at once and forever.
The mustard plant mentioned in the Gospels may have been either the common mustard plant which grows to a large size in the Orient, or it may have been the Salvadora persica, an arboreous plant of abundant foliage, the seeds and leaves of which have a distinct flavor of mustard.