Albert Barnes Commentary Deuteronomy 11

And know ... - Understand it this way: And acknowledge this day (for I am not addressing your children who have not known and who have not seen) the chastisement of the Lord, his greatness, and so on.

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.

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 (Numbers 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 its richness was not, as was that of Egypt, the reward of human 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 , 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; that is, He would supply at each successive season the useful conditions for productiveness.

But Egypt, a fitting 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 annual 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. An allusion is made to these mechanical appliances (Deuteronomy 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, which falls around the time of sowing, and is known as “the former” because it occurs in the early part of the Hebrew civil year, namely, in October and November. The other word refers to the spring rain, which falls in March and April, because it prepares the earth for the ingathering of the harvest. Between these two wet periods, and apart from 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.