And this knowledge was to impel them to keep the law, that they might be strong, i.e., spiritually strong (Deu 1:38), and not only go into the promised land, but also live long therein (cf. Deu 4:26; Deu 6:3). - In Deu 11:10-12 Moses adduces a fresh motive for his admonition to keep the law with fidelity, founded upon the peculiar nature of the land. Canaan was a land the fertility of which was not dependent, like that of Egypt, upon its being watered by the hand of man, but was kept up by the rain of heaven which was sent down by God the Lord, so that it depended entirely upon the Lord how long its inhabitants should live therein. Egypt is described by Moses as a land which Israel sowed with seed, and watered with its foot like a garden of herbs. In Egypt there is hardly any rain at all (cf. Herod. ii. 4, Diod. Sic. i. 41, and other evidence in Hengstenberg's Egypt and the Books of Moses, pp. 217ff.). The watering of the land, which produces its fertility, is dependent upon the annual overflowing of the Nile, and, as this only lasts for about 100 days, upon the way in which this is made available for the whole year, namely, by the construction of canals and ponds throughout the land, to which the water is conducted from the Nile by forcing machines, or by actually carrying it in vessels up to the fields and plantations.
(Note: Upon the ancient monuments we find not only the draw-well with the long rope, which is now called Shaduf, depicted in various ways (see Wilkinson, i. p. 35, ii. 4); but at Beni-Hassan there is a representation of two men carrying a water-vessel upon a pole on their shoulders, which they fill from a draw-well or pond, and then carry to the field (cf. Hengstenberg, Egypt and the Books of Moses, pp. 220-1).)
The expression, “with thy foot,” probably refers to the large pumping wheels still in use there, which are worked by the feet, and over which a long endless rope passes with pails attached, for drawing up the water (cf. Niebuhr, Reise, i. 149), the identity of which with the ἕλιξ described by Philo as ὑδρηλὸν ὄργανον (de confus. ling. i. 410) cannot possibly be called in question; provided, that is to say, we do not confound this ἕλιξ with the Archimedean water-screw mentioned by Diod. Sic. i. 34, and described more minutely at v. 37, the construction of which was entirely different (see my Archaeology, ii. pp. 111-2). - The Egyptians, as genuine heathen, were so thoroughly conscious of this peculiar characteristic of their land, which made its fertility far more dependent upon the labour of human hands than upon the rain of heaven or divine providence, that Herodotus (ii. 13) represents them as saying, “The Greeks, with their dependence upon the gods, might be disappointed in their brightest hopes and suffer dreadfully from famine.” The land of Canaan yielded no support to such godless self-exaltation, for it was “a land of mountains and valleys, and drank water of the rain of heaven” (לְ before מָטָר, to denote the external cause; see Ewald, §217, d.); i.e., it received its watering, the main condition of all fertility, from the rain, by the way of the rain, and therefore through the providential care of God.