Language:
كتاب الدعوات
80
Invocations
(55)
Chapter: "Our Lord! Give us in this world that which is good and in the Hereafter that which is good and save us from the torment of the Fire!"
(55)
بَابُ قَوْلِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «رَبَّنَا آتِنَا فِي الدُّنْيَا حَسَنَةً»
Sahih al-Bukhari 6389

Narrated Anas:

The most frequent invocation of The Prophet (ﷺ) was: "O Allah! Give to us in the world that which is good and in the Hereafter that which is good, and save us from the torment of the Fire." (2.201)

حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا عَبْدُ الْوَارِثِ، عَنْ عَبْدِ الْعَزِيزِ، عَنْ أَنَسٍ، قَالَ كَانَ أَكْثَرُ دُعَاءِ النَّبِيِّ صلى الله عليه وسلم ‏ "‏ اللَّهُمَّ رَبَّنَا آتِنَا فِي الدُّنْيَا حَسَنَةً، وَفِي الآخِرَةِ حَسَنَةً، وَقِنَا عَذَابَ النَّارِ ‏"‏‏.‏
Reference : Sahih al-Bukhari 6389
In-book reference : Book 80, Hadith 84
USC-MSA web (English) reference : Vol. 8, Book 75, Hadith 398
  (deprecated numbering scheme)