Surah Al-Furqan, Ayah 50

This is also part of His complete power and supreme authority:

Allah sends the winds as heralds of glad tidings, i.e., they bring the clouds behind them. The winds are of many different types, depending on the purpose for which they are sent. Some of them form the clouds, others carry the clouds or drive them, and others come ahead of the clouds as heralds announcing their coming. Some of them come before that to stir up the earth, and some of them fertilize or "seed" the clouds to make it rain. Allah says:

وَأَنزَلْنَا مِنَ السَّمَآءِ مَآءً طَهُوراً

(and We send down pure water from the sky), meaning, as a means of purifying it. Abu Sa`id said, "It was said: "O Messenger of Allah, can we perform Wudu' with the water of the well of Buda`ah For it is a well in which rubbish and the flesh of dogs are thrown. He said:

وَلَقَدْ صَرَّ‌فْنَاهُ بَيْنَهُمْ (And We have distributed it (the water) among them - 25:50). The verse says that We keep rotating the rainfall, that is, it sometimes falls in one locality and sometimes in another. Then sometimes a locality receives in one year more rain and in subsequent years less. Sayyidna ` Abdullah Ibn ` Abbas ؓ says that the presumption of some people that the quantity of rains varies from year to year is not really correct. In fact the aggregate amount of water sent down to the world (at macro-level) is equal every year. However, according to Allah's will, its allocation for different territories may change from year to year. Sometimes the quantity of water is curtailed for a specific habitation as a punishment and warning for it, and sometimes the quantity of rain is increased for a particular population, again as a punishment for their misdeeds. Thus the water that was a blessing in its origin turns into a torment for the people who are ungrateful and disobedient.

The phenomenon which in the present age is known as the axial rotation of the earth has been set down here in layman’s language. The earth rotates on its axis once in twenty-four hours, due to which day and night follow upon each other. This is a wonderful miracle of Almighty God’s power. Had there been no axial rotation of the earth, half of it would have been continuously under the blazing sun, while the other half would have been continuously enveloped by night. Thus it would have been extremely difficult to live on the earth. There are many lessons in this system of the earth. Just as the light of day necessarily follows the darkness of night; in the same way untruth will be followed by Truth. Similarly, waking up in the morning after sleeping at night is symbolic of resurrection in the life after death. Likewise, there is a lesson hidden in the system of the rains. Just as the dead earth is revived thanks to the rains, so also does God’s guidance instil faith and fear of God in a heart which otherwise would have become as lifeless as an arid land.