Musannaf Ibn Abi Shayba 3:3599

Yazid ibn Harun narrated to us, he said: Isma'il ibn Abi Khalid narrated to us, from al-Musayyib ibn Rafi', from 'Anbasa ibn Abi Sufyan, from Umm Habibah bint Abi Sufyan, from the Prophet (peace and blessings of Allah be upon him), who said: "Whoever prays twelve prostrations in a day and a night, besides the obligatory ones, Allah will build for him a house in Paradise."