Language:
كتاب النكاح
67
Wedlock, Marriage (Nikaah)
(2)
Chapter: "Whoever is able to marry, should marry..."
(2)
بَابُ قَوْلِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «مَنِ اسْتَطَاعَ مِنْكُمُ الْبَاءَةَ فَلْيَتَزَوَّجْ، لأَنَّهُ أَغَضُّ لِلْبَصَرِ وَأَحْصَنُ لِلْفَرْجِ»، وَهَلْ يَتَزَوَّجُ مَنْ لاَ أَرَبَ لَهُ فِي النِّكَاحِ
Sahih al-Bukhari 5065

Narrated 'Alqama:

While I was with `Abdullah, `Uthman met him at Mina and said, "O Abu `Abdur-Rahman ! I have something to say to you." So both of them went aside and `Uthman said, "O Abu `Abdur-Rah. man! Shall we marry you to a virgin who will make you remember your past days?" When `Abdullah felt that he was not in need of that, he beckoned me (to join him) saying, "O 'Alqama!" Then I heard him saying (in reply to `Uthman), "As you have said that, (I tell you that) the Prophet (ﷺ) once said to us, 'O young people! Whoever among you is able to marry, should marry, and whoever is not able to marry, is recommended to fast, as fasting diminishes his sexual power.

حَدَّثَنَا عُمَرُ بْنُ حَفْصٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا الأَعْمَشُ، قَالَ حَدَّثَنِي إِبْرَاهِيمُ، عَنْ عَلْقَمَةَ، قَالَ كُنْتُ مَعَ عَبْدِ اللَّهِ فَلَقِيَهُ عُثْمَانُ بِمِنًى فَقَالَ يَا أَبَا عَبْدِ الرَّحْمَنِ إِنَّ لِي إِلَيْكَ حَاجَةً‏.‏ فَخَلَيَا فَقَالَ عُثْمَانُ هَلْ لَكَ يَا أَبَا عَبْدِ الرَّحْمَنِ فِي أَنْ نُزَوِّجَكَ بِكْرًا، تُذَكِّرُكَ مَا كُنْتَ تَعْهَدُ، فَلَمَّا رَأَى عَبْدُ اللَّهِ أَنْ لَيْسَ لَهُ حَاجَةٌ إِلَى هَذَا أَشَارَ إِلَىَّ فَقَالَ يَا عَلْقَمَةُ، فَانْتَهَيْتُ إِلَيْهِ وَهْوَ يَقُولُ أَمَا لَئِنْ قُلْتَ ذَلِكَ لَقَدْ قَالَ لَنَا النَّبِيُّ صلى الله عليه وسلم ‏ "‏ يَا مَعْشَرَ الشَّبَابِ مَنِ اسْتَطَاعَ مِنْكُمُ الْبَاءَةَ فَلْيَتَزَوَّجْ، وَمَنْ لَمْ يَسْتَطِعْ فَعَلَيْهِ بِالصَّوْمِ فَإِنَّهُ لَهُ وِجَاءٌ ‏"‏‏.‏
Reference : Sahih al-Bukhari 5065
In-book reference : Book 67, Hadith 3
USC-MSA web (English) reference : Vol. 7, Book 62, Hadith 3
  (deprecated numbering scheme)