Notes on the Bible, by Albert Barnes, , at sacred-texts.com
And know ... - Render it: And own ye this day (for I have not to do with your children which have not known and which have not seen) the chastisement of the Lord, his greatness, etc.
The "chastisement" consisted in the many mighty acts, both of punishment and mercy, through which God had guided them from Egypt to the borders of the promised land.
See the margin. literally, "every living thing at their feet." The expression does not mean their goods, which would be included in their "households and tents," but their followers Num 16:32.
Another motive for fidelity is added, namely, the entire dependence of the promised land upon God for its fertility. It was "a land flowing with milk and honey;" yet this its richness was not, as was that of Egypt, the reward of truman skill and labor, but was, on the contrary, the gift of God simply and entirely; the effect of "the former and the latter rains" sent by Him. The spiritual significance of these and many other such peculiarities of the promised land must not be overlooked.
Egypt and Canaan are distinguished in this and the following verses, by certain of their most remarkable physical traits. Canaan as a mountainous country (compare Deu 3:25 note) was well watered, but by the rains of heaven, on which it absolutely depended for its crops. Artificial irrigation could do nothing to remedy this dependence. Hence, it was a land on which, so long as God's people were faithful and consequently prosperous, "the eyes of God" would always be: i. e., He would supply at each successive season (compare Deu 11:14-15) the useful conditions of productiveness. But Egypt, fit emblem here as elsewhere of the world of nature in distinction from the world of grace, though of course deriving its all ultimately from the Giver of all good things, yet directly and immediately owed its riches and plenty to human ingenuity and capital. It enjoyed no rain worth speaking of, but drew its water supply from the annum overflowing of the Nile. This only lasts about a hundred days; but is rendered available for agricultural purposes throughout the year by an elaborate and costly system of tanks, canals, forcing machines, etc. To these mechanical appliances allusion is made in Deu 11:10. The inhabitants of Egypt probably watered "with the foot" in two ways, namely, by means of tread-wheels working sets of pumps, and by means of artificial channels connected with reservoirs, and opened, turned, or closed by the feet. Both methods are still in use in Egypt.
The first rain and the latter rain - The former is the proper term for the autumn rain, falling about the time of sowing, and which may be named "the former," as occurring in the early part of the Hebrew civil year, namely, in October and November. The other word is applied to the spring rain, which falls in March and April, because it fits the earth for the ingathering of harvest. Between these two wet periods, and except them, there was little or no rain in Canaan.
The sense is: "Keep the covenant faithfully, and so shall your own and your children's days be multiplied as long as the heaven covers the earth." The promise of Canaan to Israel was thus a perpetual promise, but also a conditional one.
Thou shalt put the blessing upon mount Gerizim - literally, thou shalt give, i. e., "give" utterance to it. On the ceremony see Deu 27:14 ff.
Mount Gerizim, barren like Ebal, was probably selected as the hill of benediction because it was the southernmost of the two, the south being the region, according to Hebrew ideas, of light, and so of life and blessing. The situation of the mountains is described more accurately in Deu 11:30. The words "by the way where the sun goeth down," should run, beyond the road of the west; i. e., on the further side of the main track which ran from Syria and Damascus to Jerusalem and Egypt through the center of Palestine. This is called "the way of the west" in contrast to the ether main route from Damascus to the south which passed through the district east of Jordan. The further specifications "Gilgal" and "the plains (rather, the oaks, compare Gen 12:6 note) of Moreh," are added to define more particularly the section of Canaanites intended.
This Gilgal is perhaps to be found in Jiljilia, a large village about twelve miles south of Gerizim.