Midrasch zu Ijow 37:11

R. Ami said: "Rains are withheld solely on account of the sin of robbery; as it is said (Job 36, 32) He covereth His hands with the lightning. His hands, refers to the robbery; as it is said (Jonah 3, 8) And from the violence which is in their hands; and light, refers to rain; as it is said (Job 37, 11) He spreadeth abroad the cloud of His lightning. What is its remedy? Increasing prayer; as it is said (Ib. 36, 32) And giveth it a charge B'mafgiah; and Mafgia refers to prayer; as it is said (Jer. 7, 16) Therefore pray not thou for this people, etc., neither Tifga, (shall thou make intercession to Me)."

Eight things were created on the first day, namely, Heaven, Earth, Light, Darkness, Tohu (Chaos), Bohu (Void), Wind (or Spirit), and Water, as it is said, "And the wind of God was moving upon the face of the waters" (Gen. 1:2). Some (wise men) say that day and night also, as it is said, And there was evening and morning, one day (Gen. 1:5). Eight things were created on the second day, namely, the Well, the Manna, the Rod, the Rainbow, the art of writing, the written characters, the Garments, and the destroying spirits. Ten things arose in the thought (of the Creator), namely, Jerusalem," the spirits of the patriarchs, the paths of the righteous, Hell (Gehenom), the waters of the flood, the second tables, the shabbat, the temple and the light of the world to come.

The clouds draw water from the depths, as it is said, "He causeth the vapours to ascend from the ends of the earth" (Ps. 135:7), and in every place where the King commands them, there they cause rain (to fall), and forthwith the earth becomes fruitful and yields produce like a widow who becomes pregnant through debauchery. But when the Holy One, blessed be He, desires to bless the produce of the earth, and to give provision to the creatures, He opens the good treasuries in heaven and sends rain upon the earth, namely, the fructifying rain, and forthwith the earth becomes fruitful like a bride who conceives from her first husband and produces offspring of blessing, as it is said, "The Lord shall open unto thee his good treasury the heaven" (Deut. 28:12).

Or, because Eretz Yisrael is surrounded with mountains, I might think that what is revealed (i.e., exposed) drinks (rain), and that what is concealed does not; it is, therefore, written (Devarim 11:11) "From the rain of the heavens you will drink water" — both the revealed and the concealed. And thus is it written (Job 37:11) "Af-Bri (the plenipotentiary of rain) will load the cloud. He (Af-Bri) will scatter the cloud of His rain, and he around (the mountain) (will guide it) with his stratagems." So that clouds surround it and water it from every side.