Language:
كتاب النكاح
67  
Wedlock, Marriage (Nikaah)
(36)
Chapter: (It is permissible) to look at a woman before marrying.
(35)
باب النَّظَرِ إِلَى الْمَرْأَةِ قَبْلَ التَّزْوِيجِ
Sahih al-Bukhari 5125

Narrated `Aisha:

Allah's Messenger (ﷺ) said (to me), "You were shown to me in a dream. An angel brought you to me, wrapped in a piece of silken cloth, and said to me, 'This is your wife.' I removed the piece of cloth from your face, and there you were. I said to myself. 'If it is from Allah, then it will surely be.' "

حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ هِشَامٍ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ قَالَتْ قَالَ لِي رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ رَأَيْتُكِ فِي الْمَنَامِ يَجِيءُ بِكِ الْمَلَكُ فِي سَرَقَةٍ مِنْ حَرِيرٍ فَقَالَ لِي هَذِهِ امْرَأَتُكَ‏.‏ فَكَشَفْتُ عَنْ وَجْهِكِ الثَّوْبَ، فَإِذَا أَنْتِ هِيَ فَقُلْتُ إِنْ يَكُ هَذَا مِنْ عِنْدِ اللَّهِ يُمْضِهِ ‏"‏‏.‏
Reference : Sahih al-Bukhari 5125
In-book reference : Book 67, Hadith 61
USC-MSA web (English) reference : Vol. 7, Book 62, Hadith 57
  (deprecated numbering scheme)