Sunnah.com reference : Book 2, Hadith 450English translation : Book 2, Hadith 517Arabic reference : Book 2, Hadith 519
Narrated [Anas (RA)]:
Rain fell upon us while we were with Allah's Messenger (ﷺ). He opened his garment till some of the rain fell upon him. He then said, "It has only recently been created by its Rabb."

[Reported by Muslim].
وَعَنْ أَنَسٍ قَالَ: { أَصَابَنَا ‏-وَنَحْنُ مَعَ رَسُولِ اَللَّهِ‏- ‏- صلى الله عليه وسلم ‏-مَطَرٌ قَالَ: فَحَسَرَ ثَوْبَهُ, حَتَّى أَصَابَهُ مِنَ اَلْمَطَرِ, وَقَالَ: 
"إِنَّهُ حَدِيثُ عَهْدٍ بِرَبِّهِ" }  رَوَاهُ مُسْلِمٌ.‏  1‏ .‏‏1 ‏- صحيح.‏ رواه مسلم (898)‏.‏