Hadith 500300
Chapter 1: The Times of Prayer - كتاب وقوت الصلاة
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِذَا اشْتَدَّ الْحَرُّ فَأَبْرِدُوا عَنِ الصَّلاَةِ فَإِنَّ شِدَّةَ الْحَرِّ مِنْ فَيْحِ جَهَنَّمَ " .
Yahya related to me from Malik from Abu'z Zinad from al-Araj from Abu Hurayra that the Messenger of Allah, may Allah bless him and grant him peace, said, "When the heat is fierce, wait until it gets cooler before you do the prayer, for scorching heat is from the blast of Jahannam."
Reference Muwatta Malik 500300
USC-MSA web (English) reference : Book 1, Hadith 29