Language:
كتاب اللباس
77  
Dress
(83)
Chapter: The use of false hair
(83)
باب الْوَصْلِ فِي الشَّعَرِ
Sahih al-Bukhari 5936

Narrated Asma':

(the daughter of Abu Bakr) Allah's Messenger (ﷺ) has cursed such a lady as artificially lengthening (her or someone else's) hair or gets her hair lengthened.

حَدَّثَنَا آدَمُ، حَدَّثَنَا شُعْبَةُ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنِ امْرَأَتِهِ، فَاطِمَةَ عَنْ أَسْمَاءَ بِنْتِ أَبِي بَكْرٍ، قَالَتْ لَعَنَ النَّبِيُّ صلى الله عليه وسلم الْوَاصِلَةَ وَالْمُسْتَوْصِلَةَ‏.‏
Reference : Sahih al-Bukhari 5936
In-book reference : Book 77, Hadith 151
USC-MSA web (English) reference : Vol. 7, Book 72, Hadith 819
  (deprecated numbering scheme)