They were caught in rain at Hunayn, so the Messenger of Allah ﷺ said, "Pray in your dwellings."
حدثنا يحيى بن سعيد عن شعبة حدثنا قتادة
أنهم أصابهم مطر بحنين فقال رسول الله ﷺ صلوا في الرحال
No references are available.
Its isnad is sahih, mentioned previously in 20589.