Muwatta Malik 27
Sahih Lighairihi Graded by Salim al-Hilali Book of The Times of Prayer · Hadith 27 of 1,858حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ عَطَاءِ بْنِ يَسَارٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِنَّ شِدَّةَ الْحَرِّ مِنْ فَيْحِ جَهَنَّمَ فَإِذَا اشْتَدَّ الْحَرُّ فَأَبْرِدُوا عَنِ الصَّلاَةِ " . وَقَالَ " اشْتَكَتِ النَّارُ إِلَى رَبِّهَا فَقَالَتْ يَا رَبِّ أَكَلَ بَعْضِي بَعْضًا . فَأَذِنَ لَهَا بِنَفَسَيْنِ فِي كُلِّ عَامٍ نَفَسٍ فِي الشِّتَاءِ وَنَفَسٍ فِي الصَّيْفِ " .
Yahya related to me from Malik from Zayd ibn Aslam from Ata ibn Yasar that the Messenger of Allah, may Allah bless him and grant him peace, said, "Scorching heat is a part of the blast of Jahannam. So, when the heat is fierce, delay the prayer until it gets cooler." He added in explanation, "The Fire complained to its Lord and said, 'My Lord, part of me has eaten another part,' so He allowed it two breaths in every year, a breath in winter and a breath in summer
References
Muwatta Malik 27
In-book: Book 1, Hadith 27 Source: hadith-api (fawazahmed0)