مُوَطَّأُ مَالِكٍ
Muwatta Malik 10
The Times of Prayer
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ إِسْحَاقَ بْنِ عَبْدِ اللَّهِ بْنِ أَبِي طَلْحَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّهُ قَالَ كُنَّا نُصَلِّي الْعَصْرَ ثُمَّ يَخْرُجُ الإِنْسَانُ إِلَى بَنِي عَمْرِو بْنِ عَوْفٍ فَيَجِدُهُمْ يُصَلُّونَ الْعَصْرَ .
Yahya related to me from Malik from Ishaq ibn Abdullah ibn Abi Talha that Anas ibn Malik said, "We would pray asr and anyone who then went to the Bani Amr ibn Awf would find them praying asr."
Arabic/English book reference: Book 1, Hadith 10