Sahih al-Bukhari 2994
Sahih al-Bukhari · Book 56: Fighting for the Cause of Allah (Jihaad) · To say Takbir on ascending a high place
Narrated Jabir:
حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ ، حَدَّثَنَا ابْنُ أَبِي عَدِيٍّ ، عَنْ شُعْبَةَ ، عَنْ حُصَيْنٍ ، عَنْ سَالِمٍ ، عَنْ جَابِرٍ ـ رضى الله عنه ـ قَالَ كُنَّا إِذَا صَعِدْنَا كَبَّرْنَا، وَإِذَا تَصَوَّبْنَا سَبَّحْنَا.
Whenever we went up a place we would say Takbir, and whenever we went down we would say, "Subhan Allah."