Sunan an-Nasa'i, Book 6, Hadith 503 (In-Book) ⓘ
Khalid bin Dinar Abu Khaldah said: "I heard Anas bin Malik say: 'When it was hot, the Messenger of Allah would wait until it cooled down to pray, and when it was cold he would hasten to pray.'"
أَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا أَبُو سَعِيدٍ، مَوْلَى بَنِي هَاشِمٍ قَالَ حَدَّثَنَا خَالِدُ بْنُ دِينَارٍ أَبُو خَلْدَةَ، قَالَ سَمِعْتُ أَنَسَ بْنَ مَالِكٍ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم إِذَا كَانَ الْحَرُّ أَبْرَدَ بِالصَّلاَةِ وَإِذَا كَانَ الْبَرْدُ عَجَّلَ .
also referenced under: Volume 1, Book 6, Hadith 500 (DarusSalam)