"And We have sent down rain from the sky in a measured amount." The interpretation of al-Kalbi: Meaning the rivers, springs, and wells.
﴿وَأَنْزَلْنَا مِنَ السَّمَاءِ مَاءً بِقَدَرٍ﴾ تَفْسِيرُ الْكَلْبِيِّ: يَعْنِي: الْأَنْهَارَ وَالْعُيُونَ والآبار.