And We have sent down rain from the sky in a measured (23:18)

Almuntakhab Fi Tafsir Alquran Alkarim

And We sent down from the floor of the vault of heaven rain water in due measure and We settled it on the planet earth partly without and partly within - enough to effect the necessary equilibrium, between the opposing forces of land and water, between cloud formation and fresh water in rivers and lakes maintaining life, between the clouds and the water deposited underground- and We are certainly able to make it vanish

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(23:18) And We sent down rain from the sky in due measure and lodged it in the earth : *17 and We are able to take it away as We will. *18

And We have sent down rain from the sky in a measured meaning

*17) The "rain" may refer to the rainfall, which comes down every now and then. It may also refer to the great store of water which Allah sent down at the time of the creation of the earth to fulfil its various needs till the Last Day, and which still exists in the shape of seas, lakes, sub-soil water, etc. It is the same water which evaporates in summer and freezes in winter and is carried by winds from place to place and spread over the earth by rivers, springs and wells to cause the growth of multitudes of things, and then is again restored to the seas, lakes, etc. Neither has this store of water been decreased by a drop nor was there any need to increase it by a drop since its creation. Today it is too well known how water comes about by the combination of oxygen and hydrogen in a certain ratio. The question is why can't more water be produced when oxygen and hydrogen still exist in abundance in the world? Who caused them to combine in the proper ratio in the beginning to produce oceans of water and who now stops them from coming together to produce an extra drop? Then when water evaporates, who causes oxygen and hydrogen to remain combined .n water vapours even in the gaseous state. Have the atheists and polytheists, who believe in independent deities for water, air, summer and ! winter, any answer to this question?
*18) This is to warn that Allah is able to take away the water if He so wills, and deprive the world of its most important means of life. Thus, this verse is more comprehensive in meaning than verse 30 of Surah Al-hulk (LXVII):
"Ask them: Have you ever considered that if the water of your wells should sink down into the earth, who would then restore to you running springs of water?"
 

And We have sent down rain from the sky in a measured meaning in Urdu

اور آسمان سے ہم نے ٹھیک حساب کے مطابق ایک خاص مقدار میں پانی اتارا اور اس کو زمین میں ٹھیرا دیا ہم اُسے جس طرح چاہیں غائب کر سکتے ہیں