Abu Bakr bin Abd al-Rahman bin al-Harith bin Hisham narrates from Sayyidah Umm Salamah (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) married her, and he mentioned various things in it; he said: "If you wish, I will stay with you for seven days, and I will stay with the other wives for seven days as well."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب القسم والنشوز / 14759