(100) باب إِذَا تَزَوَّجَ الْبِكْرَ عَلَى الثَّيِّبِ
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.
Reference: Sahih al-Bukhari 5213
In-book reference: Book 67, Hadith 146
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 62, Hadith 140