Musannaf Ibn Abi Shayba 3:3601

Narrated to us Abd al-A’la, from al-Jurayri, from Ibn Buraydah, from Ka’b, who said: Twelve rak’ahs. Whoever prays them in a day, besides the obligatory ones, will enter Paradise, or a house will be built for him in Paradise: two rak’ahs before the dawn prayer, two rak’ahs of al-Duha, four rak’ahs before the noon prayer, two rak’ahs after it, and two rak’ahs after the sunset prayer.