Sahih al-Bukhari 1023Book 15, Hadith 18
حَدَّثَنَا أَبُو الْيَمَانِ، قَالَ أَخْبَرَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، قَالَ حَدَّثَنِي عَبَّادُ بْنُ تَمِيمٍ، أَنَّ عَمَّهُ ـ وَكَانَ مِنْ أَصْحَابِ النَّبِيِّ صلى الله عليه وسلم أَخْبَرَهُ أَنَّ النَّبِيَّ صلى الله عليه وسلم خَرَجَ بِالنَّاسِ يَسْتَسْقِي لَهُمْ، فَقَامَ فَدَعَا اللَّهَ قَائِمًا، ثُمَّ تَوَجَّهَ قِبَلَ الْقِبْلَةِ، وَحَوَّلَ رِدَاءَهُ فَأُسْقُوا.
that his uncle (who was one of the companions of the Prophet) had told him, "The Prophet (ﷺ) went out with the people to invoke Allah for rain for them. He stood up and invoked Allah for rain, then faced the Qibla and turned his cloak (inside out) and it rained."