Musnad Abu Ya'la al-Mawsili 219:3

Zuhayr narrated to us, Isma'il ibn Ibrahim narrated to us, Dawud ibn Abi Hind narrated to us, al-Nu'man ibn Salim informed us, from 'Amr ibn Aws, who said: 'Anbasa ibn Abi Sufyan said to me, "Shall I not narrate to you a hadith that Umm Habibah bint Abi Sufyan narrated to us?" I said, "Yes." He said, "And I have not seen it—" He said, "And it is nothing but glad tidings to you." He said, "She narrated to us that the Messenger of Allah (peace and blessings of Allah be upon him) said: 'Whoever prays twelve prostrations (rak'ahs) in a day voluntarily, a house will be built for him in Paradise because of them.'" Umm Habibah said, "I have not abandoned them since I heard them." Al-Nu'man said, "I have not abandoned them since I heard them from 'Amr." Dawud said, "As for us, we pray them and we abandon them."