Sayyiduna Anas bin Malik (may Allah be pleased with him) said: We offered four rak‘ahs of Zuhr prayer with the Messenger of Allah (peace and blessings be upon him) in Madinah, and at Dhul-Hulaifah he offered two rak‘ahs (qasr) of ‘Asr.
Hadith Referenceسنن دارمي / من كتاب الصللاة / 1546