I saw the Messenger of Allah ﷺ extending his hands until I could see the whiteness of his armpits. Sulayman said, "I believe he was supplicating for rain."
رأيت رسول الله ﷺ مادا يديه، حتى رأيت بياض إبطيه. قال سليمان: ظننته يدعو في الاستسقاء.
Ibn Majah (1271) and Ibn Khuzayma (1413) both narrated it through Sulayman Taymi, from Baraka - who is Abu Walid - from Bashir bin Nuhayk, from Abu Hurairah, and he related it. The wording is that of Ibn Khuzayma, and its chain of transmission is sahih.