كتاب النكاح
16  
The Book of Marriage
(11)
Chapter: It is recommended to get married and arrange marriages in Shawwal, and it is recommended to consummate the marriage in that month
(11)
باب اسْتِحْبَابِ التَّزَوُّجِ وَالتَّزْوِيجِ فِي شَوَّالٍ وَاسْتِحْبَابِ الدُّخُولِ فِيهِ ‏
Sahih Muslim 1423 a

'A'isha (Allah be pleased with her) reported:

Allah's Messenger (ﷺ) contracted marriage with me in Shawwal and took me to his house as a bride during Shawwal. And who among the wives of Allah's Messenger (ﷺ) was dearer to him than I, and' A'isha liked that the women (of her family) should enter the houses as brides during the month of Shawwal.
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَزُهَيْرُ بْنُ حَرْبٍ، - وَاللَّفْظُ لِزُهَيْرٍ - قَالاَ حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا سُفْيَانُ، عَنْ إِسْمَاعِيلَ بْنِ أُمَيَّةَ، عَنْ عَبْدِ اللَّهِ بْنِ عُرْوَةَ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ، قَالَتْ تَزَوَّجَنِي رَسُولُ اللَّهِ صلى الله عليه وسلم فِي شَوَّالٍ وَبَنَى بِي فِي شَوَّالٍ فَأَىُّ نِسَاءِ رَسُولِ اللَّهِ صلى الله عليه وسلم كَانَ أَحْظَى عِنْدَهُ مِنِّي ‏.‏ قَالَ وَكَانَتْ عَائِشَةُ تَسْتَحِبُّ أَنْ تُدْخِلَ نِسَاءَهَا فِي شَوَّالٍ ‏.‏
Reference : Sahih Muslim 1423a
In-book reference : Book 16, Hadith 85
USC-MSA web (English) reference : Book 8, Hadith 3312
  (deprecated numbering scheme)