(9) باب الإِبْرَادِ بِالظُّهْرِ فِي شِدَّةِ الْحَرِّ
Narrated Abu Sa`id:
that Allah's Messenger (ﷺ) said, "Pray Zuhr prayer when it becomes (a bit) cooler as the severity of heat is from the raging of the Hell-fire."
Reference: Sahih al-Bukhari 538
In-book reference: Book 9, Hadith 15
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 10, Hadith 513