The finely ground substance of any cereal. The earliest and most simple way of crushing grain consisted in pounding it in a mortar, producing a coarse flour, or rather different grades of grits (comp. the preparation of the manna, Num. xi. 8). In order to obtain fine flour the grain, it seems, was pulverized between two stones (see illustration in Erman, "Aegypten und Aegyptisches Leben im Altertum," p. 268; Bliss, "A Mound of Many Cities," p. 85). But as far back as can be traced the Israelites used a mill for preparing fine flour. A small hand-mill was used down to a late date, but in the Gospels mills worked by asses are mentioned (μνλος όνικáς, Matt. xviii. 6, R. V., margin). Each household prepared its own flour—hence the prohibition to take a hand-mill in pledge from the poor (Deut. xxiv. 6); the heavy work of grinding was the task of the women and the female slaves (Ex. xi. 5; Isa. xlvii. 2; Matt. xxiv. 41), or of captives (Judges xvi. 21; Lam. v. 13).
The ancient mill could hardly have differed from that now used in Palestine, which consists of two circular stones ("pelaḥ"); hence the designation "reḥayim" (lit. "the two millstones"; comp. Deut. xxiv. 6; Isa. xlvii. 2). The mill is also known as "ṭaḥanah" (Eccl. xii. 4; "ṭeḥon," Lam. v. 15). At present these stones, generally made of basalt, are about 40-48 cm. in diameter and about 10 cm. thick. The nether stone ("pelaḥ taḥtit") is fixed and is especially hard (Job xli. 16). It is somewhat convex, with a small plug of hard wood in the center. The upper stone is correspondingly concaved on the nether side, with a funnel-shaped hole in the center, into which the plug of the nether stone is fitted. On the edge is a peg ("yad") used as a handle. The upper stone is turned by the grinder around the plug of the nether stone; hence its name "pelaḥ rekeb," or merely "rekeb" ("the wagon"; Judges ix. 53; II Sam. xi. 21; Deut. xxiv. 6). The grain is poured by hand through the funnel-shaped hole of the upper stone, and the flour, dropping from the edge of the nether stone, is collected on a cloth spread beneath.
The grain commonly made into bread was barley and wheat, especially the latter, spelt ("kussemet") being evidently used in special cases only (Ezek. iv. 9). Wheat bread was the superior article, barley bread being the food of the poor. In the ritual, barley flour was used for the offering of jealousy (Num. v. 15). Wheat flour was prepared in two different grades. The flour that was generally used for baking was called "ḳemaḥ," being fine or coarse as it fell from the mill; and from this a finer flour (which is probably the meaning of the term "solet" = υεμίδυλις) was separated by means of a hair-sieve. This fine flour, the "fat of the wheat" (Deut. xxxii. 14; Ps. lxxxi. 17, cxlvii. 14), was worth twice as much as barley (II Kings vii. 1, 16, 18; comp. Erman, l. c. p. 266, as to the two kinds of flour imported from Syria into Egypt). With the one exception mentioned above, the use of fine flour ("solet") is prescribed throughout in the ritual; the conclusion is not warranted, however, that the ordinary flour used for daily consumption was not employed for sacrifices in ancient times.