sent forth the winds as heralds of His mercy,” meaning: the rain.
Muhammad said: “nushuran” (heralds/spreaders) with the damma is the plural of “nashur,” like “rasul” (messenger) and “rusul” (messengers). “And We have sent down from the sky water,” meaning: the rain, “pure,” for the believers, to purify themselves with it from ritual impurities (ahdath) and major ritual impurity (janaba).
أَرْسَلَ الرِّيَاحَ نُشْرًا بَيْنَ يَدَيْ رَحْمَتِهِ﴾ يَعْنِي: الْمَطَرَ.
قَالَ مُحَمَّدٌ: (نُشُرًا) بِالضَّمِّ جَمْعُ: نَشُورٍ؛ مِثْلَ: رَسُولٌ وَرُسُلٌ. ﴿وَأَنْزَلْنَا مِنَ السَّمَاءِ مَاء﴾ يَعْنِي: الْمَطَر ﴿طهُورا﴾ لِلْمُؤْمِنِينَ يَتَطَهَّرُونَ بِهِ مِنَ الْأَحْدَاثِ والجنابة