The Book of Marriage (Kitab Al-Nikah)
Muslim :: Book 8 : Hadith 3444
Ibn Abu Bakr b. Abd al-Rahman reported that when Allah's Messenger (may peace be upon him) married Umm Salama and she stayed with him (during the night), and it was dawn, he (the Holy Prophet) said to her: There is no lack of estimation for you on the part of your husband. So if you desire I can spend a week with you, and if you like I may spend three (nights). and then I will visit you in turn. She said: Spend three (nights).