Sunan an-Nasa'i, Book 5, Hadith 30 (In-Book) ⓘ
It was narrated from Anas bin Malik that the Prophet prayed Zuhr in Al-Madinah, four Rak'ahs, and he prayed 'Asr in Dhul-Hulaifah, two Rak'ahs.
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا حَمَّادٌ، عَنْ أَيُّوبَ، عَنْ أَبِي قِلاَبَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم صَلَّى الظُّهْرَ بِالْمَدِينَةِ أَرْبَعًا وَصَلَّى الْعَصْرَ بِذِي الْحُلَيْفَةِ رَكْعَتَيْنِ .
also referenced under: Hadith 477 (Reference) & Volume 1, Book 5, Hadith 478 (DarusSalam)