by Imam Malik, translation by A'isha `Abdarahman at-Tarjumana and Ya`qub Johnson , Volume: Marriage
Chapter: Wedding Nights of Virgins and Women Previously Married
Yahya related to me from Malik from Abdullah ibn Abi Bakr ibn Muhammad ibn Amr ibn Hazm from Abd al-Malik ibn Abi Bakr ibn Abd ar-Rahman ibn al-Harith ibn Hisham al-Makhzumi from his father that when the Messenger of Allah, may Allah bless him and grant him peace, married Umm Salama and then spent the night with her, he said to her, "You are not being humbled in your right. If you wish, I will stay with you for seven nights as I stayed seven nights with the others. If you wish, I will stay with you for three nights, and then visit the others in turn." She said, "Stay three nights."
Yahya related to me from Malik from Humayd at-Tawil that Anas ibn Malik said, "A virgin has seven nights, and a woman who has been previously married has three nights."
Malik affirmed, "That is what is done among us."
Malik added, "If the man has another wife, he divides his time equally between them after the wedding nights. He does not count the wedding nights against the one he has just married."