It was narrated from Al-Harith from his father that when when the Messenger of Allah (ﷺ) married Umm Salamah, he stayed with her for three days, then he said:
"You are not insignificant in your husband's eyes. If you wish, I will stay with you for seven days, but then I will stay with my other wives for seven days too." (FR)
English reference (FR): Vol. 3, Book 9, Hadith 1917 (FR)
Arabic reference (FR): Book 9, Hadith 1992 (FR)