Abdullah bin Shaqiq (may Allah have mercy on him) said: I asked Sayyidah Aishah (may Allah be pleased with her) about the voluntary prayer of the Prophet (peace and blessings be upon him), and she said: He (peace and blessings be upon him) used to pray four rak'ahs before Zuhr in my house, then he (peace and blessings be upon him) would go out and lead the people in prayer, then, having finished the prayer, he would return to my house and pray two rak'ahs. He (peace and blessings be upon him) would lead the people in the Maghrib prayer and then come back to my house and offer two rak'ahs. Then he would lead them in the Isha prayer, come to my house and again offer two rak'ahs. His (peace and blessings be upon him) night prayer numbered nine rak'ahs, witr included among them. He (peace and blessings be upon him) would spend the rest of the night praying, standing, and at times sitting. When he (peace and blessings be upon him) prayed standing, he made the bowing and prostration from standing; when he recited sitting, he also made the bowing and prostration sitting. And when dawn broke, he (peace and blessings be upon him) would offer two rak'ahs and then go and lead the people in prayer.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4476
Sayyidah Aishah (may Allah be pleased with her) said that the Messenger of Allah (peace and blessings be upon him) never left four rak'ahs before Zuhr and two rak'ahs before Fajr.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4477
Yahya narrates from Shu'bah (may Allah have mercy on him) that he too mentioned the hadith in the same way, except that he said: The Messenger of Allah (peace and blessings be upon him) used to offer these before the morning prayer.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4478
Sayyidah Umm Habibah (may Allah be pleased with her) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever offers twelve voluntary rak'ahs besides the obligatory prayers, Allah Almighty will build a house for him in Paradise."
(b) Sayyidah Umm Habibah (may Allah be pleased with her) said that the Prophet (peace and blessings be upon him) said: "Whoever offers twelve voluntary rak'ahs in a day and night besides the obligatory prayers, Allah Almighty will build a house for him in Paradise." Sayyidah Umm Habibah (may Allah be pleased with her) said: After that I never left these twelve rak'ahs. Anbasah and Amr (may Allah have mercy on them) also said: We too never left these twelve rak'ahs. Al-Nu'man (may Allah have mercy on him) said: It is hardly possible that I would leave them.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4479
Umm Habibah (may Allah be pleased with her), the wife of the Prophet (peace and blessings be upon him), said that the Prophet (peace and blessings be upon him) said: "Whoever offers twelve rak'ahs, Allah Almighty will build a house for him in Paradise: four before Zuhr and two after it, two before Asr, two after Maghrib and two before the morning prayer."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4480