His uncle, who was among the companions of the Messenger of Allah ﷺ, informed him that the Prophet ﷺ went out with the people to pray for rain on their behalf. He stood and supplicated to Allah while standing, then turned toward the qiblah and reversed his cloak, and they were given rain.
أن عمه- وكان من أصحاب رسول الله ﷺ- أخبره أن النبي الله ﷺ خرج بالناس يستسقي لهم، فقام فدعا الله قائما، ثم توجه قبل القبلة، وحول رداءه فأسقوا.
Bukhari narrated it in the Book of Rain Invocation (1023), and Muslim narrated it in the Book of Rain Invocation (4/894), both from the hadith of Zuhri, who said, "Abbad bin Tamim narrated to me," and he mentioned it. The wording is that of Bukhari, and Muslim did not mention the part of it relevant to this point.