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)."'

[Al-Bukhari].

عن جابر رضي الله عنه قال: كنا إذا صعدنا كبرنا، وإذا نزلنا سبحنا. ((رواه البخاري)).