(4) باب فِي وَقْتِ صَلاَةِ الظُّهْرِ
Abu Dharr said:
We were in the company of the Prophet (ﷺ). The mu'adhdhin intended to call for the Zuhr prayer. He said: Make it cooler. He then intended to call for prayer. He said twice or thrice: Make it cooler. We then witnessed the shadow of the mounds. He then said: The intensity of heat comes from the bubbling over of the Hell ; so when the heat is violent, offer (the Zuhr) prayer when it becomes cooler.
Reference: Sunan Abi Dawud 401
In-book reference: Book 2, Hadith 11
English translation: Book 2, Hadith 401