Translation
(68) Divorce
كتاب الطلاق
(5) Chapter: Giving option to the wives.
(5) باب مَنْ خَيَّرَ نِسَاءَهُ
Sahih al-Bukhari 5262 

Narrated `Aisha:

Allah's Messenger (ﷺ) gave us the option (to remain with him or to be divorced) and we selected Allah and His Apostle . So, giving us that option was not regarded as divorce.

حَدَّثَنَا عُمَرُ بْنُ حَفْصٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا الأَعْمَشُ، حَدَّثَنَا مُسْلِمٌ، عَنْ مَسْرُوقٍ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ قَالَتْ خَيَّرَنَا رَسُولُ اللَّهِ صلى الله عليه وسلم فَاخْتَرْنَا اللَّهَ وَرَسُولَهُ، فَلَمْ يَعُدَّ ذَلِكَ عَلَيْنَا شَيْئًا‏.‏
Reference : Sahih al-Bukhari 5262
In-book reference : Book 68, Hadith 12
USC-MSA web (English) reference : Vol. 7, Book 63, Hadith 188
  (deprecated numbering scheme)