He saw the Messenger of Allah ﷺ during the prayer for rain face the qiblah, turn his cloak inside out, and raise his hands.
أخبرنا هشام بن عبد الملك أبو تقي الحمصي قال حدثنا بقية عن شعيب عن الزهري
أنه رأى رسول الله ﷺ في الاستسقاء استقبل القبلة وقلب الرداء ورفع يديه
No references are available.
Bukhari transmitted it in the Book of Rain-Seeking Prayer, chapter, Supplication During Rain-Seeking While Standing, no. 1023, from the hadith of Shuayb bin Abu Hamza. Muslim also transmitted it in the Book of Rain-Seeking Prayer, chapter, Book of Rain-Seeking Prayer, no. 4/894, from the hadith of Zuhri, with the same wording. It is also found in Al-Kubra, no. 1816.