Musnad Ahmad 1159:0

Narrated to us by Yahya ibn Sa’id, from Shu’bah, who said: Narrated to us by ‘Amr ibn Murrah, from Abu Wa’il, from Umm Habibah bint Abi Sufyan, from the Prophet (ﷺ), who said: "Whoever prays twelve rak'ahs in a day and night, a house will be built for him in Paradise because of them: four before Dhuhr and two after it, two after Maghrib, two after Isha, and two before Fajr."