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.  

عَنْ أَنَسٍ ؓ وَلَوْ شِئْتُ أَنْ أَقُولَ قَالَ النَّبِيُّ ﷺ وَلَكِنْ قَالَ السُّنَّةُ إِذَا تَزَوَّجَ الْبِكْرَ أَقَامَ عِنْدَهَا سَبْعًا وَإِذَا تَزَوَّجَ الثَّيِّبَ أَقَامَ عِنْدَهَا ثَلاَثًا  

When anyone who has already a wife marries virgin, he should stay with her for seven nights (and then turn to his other wife), but when anyone having a virgin with him (as his wife) marries a woman who has been previously married he should stay with her for three nights. Khalid (one of the narrators) said. If I were to say that it could be directly traced to the Prophet ﷺ. I would have told the truth, but he (Hadrat Anas) said: Such is the tradition.  

إِذَا تَزَوَّجَ الْبِكْرَ عَلَى الثَّيِّبِ أَقَامَ عِنْدَهَا سَبْعًا وَإِذَا تَزَوَّجَ الثَّيِّبَ عَلَى الْبِكْرِ أَقَامَ عِنْدَهَا ثَلاَثًا قَالَ خَالِدٌ وَلَوْ قُلْتُ إِنَّهُ رَفَعَهُ لَصَدَقْتُ وَلَكِنَّهُ قَالَ السُّنَّةُ كَذَلِكَ  

He (Abu Qilabah) said: "If I wish, I could say: 'The Messenger of Allah said'" but he said: "The Sunnah when a man married a virgin after he already has a wife, is that he stays with her seven (nights). And when he married a matron when he already has a wife, he stays with her three (nights)."  

قَالَ رَسُولُ اللَّهِ ﷺ وَلَكِنَّهُ قَالَ السُّنَّةُ إِذَا تَزَوَّجَ الرَّجُلُ الْبِكْرَ عَلَى امْرَأَتِهِ أَقَامَ عِنْدَهَا سَبْعًا وَإِذَا تَزَوَّجَ الثَّيِّبَ عَلَى امْرَأَتِهِ أَقَامَ عِنْدَهَا ثَلاَثًا قَالَ وَفِي الْبَابِ عَنْ أُمِّ سَلَمَةَ  

[Machine] If a virgin woman marries a previously married man, he must pay her seven days' worth of expenses. But if a previously married man marries a virgin woman, he must pay her three days' worth of expenses. Even if you say he raised the amount, you would be correct, but he said it is the sunnah (tradition) like this.  

إِذَا تَزَوَّجَ الْبِكْرَ عَلَى الثَّيِّبِ أَقَامَ عِنْدَهَا سَبْعًا وَإِذَا تَزَوَّجَ الثَّيِّبَ عَلَى الْبِكْرِ أَقَامَ عِنْدَهَا ثَلَاثًا وَلَوْ قُلْتَ إِنَّهُ رَفَعَهُ صَدَقْتَ وَلَكِنَّهُ قَالَ السُّنَّةُ كَذَلِكَ  

[Machine] The Messenger of Allah ﷺ said, "When a virgin woman marries a man who has previous experience and is not a virgin, he should spend seven nights with her. And when a man who has previous experience and is not a virgin marries a virgin woman, he should spend three nights with her."  

قَالَ رَسُولُ اللهِ ﷺ إِذَا تَزَوَّجَ الْبِكْرَ عَلَى الثَّيِّبِ أَقَامَ عِنْدَهَا سَبْعًا وَإِذَا تَزَوَّجَ الثَّيِّبَ عَلَى الْبِكْرِ أَقَامَ عِنْدَهَا ثَلَاثًا  

"إذا تزوَّجَ البكْرَ على الثَّيبِ أقامَ عنْدها سَبْعًا، وإذا تزوَّجَ الثَّيبَ على الْبكْرِ أقام عِنْدها ثلاثًا".