It is narrated from Sayyidah Umm Salamah (may Allah be pleased with her) that when the Prophet (peace and blessings be upon him) went in to her, he said to her: "You and your family hold great honour with me, and if I give you seven days, I will give each of my other wives seven days as well."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19891