Riyad as-SalihinChapter 7Hadith 296
Full Sharh — Riyad as-Salihin 296
عن جابر رضي الله عنه قال: كنا إذا صعدنا كبرنا، وإذا نزلنا سبحنا. ((رواه البخاري)).
English Translation
Jabir (May Allah be pleased with him) reported:: When we ascended (a height) we would proclaim: "Allahu Akbar (Allah is Greatest)," and when we descended (from the height) we would proclaim: "Subhan Allah (Allah is free from imperfection)."'.
Source
Riyad as-Salihin(رياض الصالحين)
The Book of Etiquette of Traveling
Hadith Number
296