Musnad Ahmad 329:26

Abu al-Yaman narrated to us, he said: Shu'ayb narrated to us, from al-Zuhri, who said: 'Abbad ibn Tamim informed me that his paternal uncle, who was one of the companions of the Prophet, may God bless him and grant him peace, [said]: "The Prophet, may God bless him and grant him peace, went out with the people to the prayer ground to pray for rain for them. He stood and supplicated while standing, then he turned toward the qibla and turned his cloak inside out." And they were given rain.