Musnad Ahmad 1007:138

Muhammad ibn Abi ‘Adi narrated to us, from al-Hajjaj—meaning Ibn Abi ‘Uthman al-Sawwaf—from Yahya—meaning Ibn Abi Kathir—from ‘Abdullah ibn Abi Qatadah, from his father, who said: The Messenger of Allah (ﷺ) used to lead us in prayer, and he would recite in the Dhuhr and ‘Asr prayers, in the first two rak‘ahs, the Opening of the Book (al-Fatihah) and two surahs. He would let us hear the verse sometimes. He used to make the first rak‘ah of the Dhuhr prayer long, and make the second one short, and likewise for the Subh (Fajr) prayer.