(10) For the land that you are about to enter and possess is not like the land of Egypt from which you have come. There the grain you sowed had to be watered by your own labors, like a vegetable garden; (11) but the land you are about to cross into and possess, a land of hills and valleys, soaks up its water from the rains of heaven. (12) It is a land that the ETERNAL your God looks after, on which the ETERNAL your God always keeps an eye, from year’s beginning to year’s end.

והשקית ברגלך [LIKE THE LAND OF EGYPT] WHICH THOU DIDST WATER WITH THY FOOT — The land of Egypt was such that you had to bring water from the Nile through your foot (i.e. you had to go to the Nile to bring water) to irrigate it — you had to rise from your sleep and to toil. Then again, the lowlying parts alone drank (were irrigated by the Nile) and not the higher land, and you had to take up water from the lower to the higher parts: but this land (Canaan), למטר השמים תשתה מים DRINKETH WATER OF THE RAIN OF HEAVEN — You may sleep soundly on your beds, and the Holy One, blessed be He, waters both low and high districts, both what is exposed and what is not exposed alike (Sifrei Devarim 38:2).

[FOR THE LAND, WHITHER THOU GOEST IN TO POSSESS IT, IS] NOT AS THE LAND OF EGYPT — “but better than it. This assurance was given to Israel upon their departure from Egypt, for they said, ‘Perhaps we will not come to a Land as good and beautiful as this’ [hence they were assured that the Land whither they were going was far better than Egypt]. One might, however, think that Scripture speaks in disdain of the Land, and Moses said thus to them: ‘It is not as the land of Egypt — but worse than it!’ Scripture states, therefore, Behold, Hebron ‘nivnethah’ (was built) seven years before Zoan in Egypt. One person [Ham] built [both] of them. Usually, a person builds the better city first and afterwards the inferior one etc.” This is Rashi’s language from the Sifre. And he further quoted what the Rabbis have interpreted in the Gemara of Tractate Kethuboth with a different point of view: “Is it possible that a man would build a house for his younger son first and afterwards for his elder son? But the meaning of the expression, Behold, Hebron ‘nivnethah’ seven years is that it was ‘built up’ superior to Zoan sevenfold.”
In line with the plain meaning of Scripture the verse here is said by way of the warnings [with which Moses has been admonishing the Israelites]. For he said to them, “Therefore shall ye keep all the commandments etc. that you may possess the Land etc. a Land flowing with milk and honey, since G-d will give the rain of your Land in its season and the Land shall yield her produce. But know you that it is not like the land of Egypt [where one can find sufficient water] to irrigate it with his feet from the streams and the pools as a garden of herbs. Instead, it is a Land of hills and valleys, and drinketh water as, the rain of heaven cometh down, not in any other way. Therefore it requires that G-d care for it always by giving it rain because it is a very thirsty Land and needs rain all year. If you transgress G-d’s Will and He does not care for it [the Land] with ‘rains of benevolence’ it is a very bad one, it cannot be sown, nor beareth, nor any herb groweth on its mountains.” All this he reviews and explains in the following section, that if ye shall hearken diligently unto My commandments, then I shall give the rain of your Land in its season, the former rain and the latter rain always, and if you will not listen He shall shut up the heaven etc. and ye shall perish by famine from off the good Land, since you will not be able to live therein without rain.
Thus this section warns in terms of the laws of nature. From it we learn that although everything is within His authority and it was but a light thing in the sight of the Eternal, blessed be He, to destroy the inhabitants of the land of Egypt and to dry up their rivers and streams, the land of Canaan, however, could be destroyed more quickly, by His not providing the showers of His mighty rain. The sick person needs merits and prayer in order that G-d heal him more than the healthy one who is not struck by illness, and such is also the way with the poor and the rich, [although] the Eternal giveth light to the eyes of them both.
And because he said, a Land which the Eternal thy G-d careth for, when he should have said, “and it drinketh water as the rain of heaven cometh down ‘whenever’ the Eternal thy G-d careth for it,” the following interpretation of our Rabbis is alluded to in the text: “But does He not care for all lands, as it is said, to cause it to rain on a land where no man is? [The answer is that the verse tells us] as it were, He exercises care for that Land alone, but through the particular care that He bestows on it, He cares also for all lands. The eyes of the Eternal thy G-d are always upon it to see what it requires and to enact new decrees for it, sometimes for good and sometimes for bad etc.” as it is written in Tractate Rosh Hashanah. There is also in this verse a profound secret, being that this Land is cared for “in all things” which is [called] Kol (All), and all lands are sustained from it in truth.