Authentic
graded by Al-Albani
Mishkat al-Masabih 1500
Narrator:Ā’ishah
وَعَنْ عَائِشَةَ قَالَتْ: إِنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ إِذَا رَأَى الْمَطَرَ قَالَ: «اللَّهُمَّ صيبا نَافِعًا» . رَوَاهُ البُخَارِيّ
‘A'isha told that when God's Messenger saw rain he said, “O God, send a beneficial downpour." Bukhari transmitted it.
Cited in Mishkat al-Masabih (No. 1500).