Sahih al-Bukhari, Hadith 5213 ⓘ
Narrated Anas: The tradition, (of the Prophet) is that if someone marries a virgin and he has already a matron wife (with him), then he should stay with the virgin for seven days; and if someone marries a matron (and he has already a virgin wife with him) then he should stay with her for three days.
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا بِشْرٌ، حَدَّثَنَا خَالِدٌ، عَنْ أَبِي قِلاَبَةَ، عَنْ أَنَسٍ ـ رضى الله عنه ـ وَلَوْ شِئْتُ أَنْ أَقُولَ قَالَ النَّبِيُّ صلى الله عليه وسلم وَلَكِنْ قَالَ السُّنَّةُ إِذَا تَزَوَّجَ الْبِكْرَ أَقَامَ عِنْدَهَا سَبْعًا، وَإِذَا تَزَوَّجَ الثَّيِّبَ أَقَامَ عِنْدَهَا ثَلاَثًا.
also referenced under: Book 67, Hadith 146 (In-Book) & Volume 7, Book 62, Hadith 140 (USC-MSA)