Musnad Ahmad 482:73

Abu Sa’id, the freed slave of Banu Hashim, narrated to us, Ibn Lahi’ah narrated to us, Mushrih ibn Ha’an Abu Mus’ab al-Mu’afiri narrated to us, he said: I heard ‘Uqbah ibn ‘Amir saying: I said: "O Messenger of Allah, has Surah al-Hajj been favored over the rest of the Qur’an with two prostrations?" He said: "Yes. So whoever does not perform them, let him not recite them."