قَالَ جَابِرٌ رضي الله عنه: (كُنَّا إِذَا صَعَدْنَا كَبَّرْنَا، وَإِذَا نَزَلْنَا سَبَّحْنَا
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Jabir (ra), said: Whenever we went up a hill we would say Allāhu Akbar (Allah is the Most Great) and when we descended we would say Subḥānallāh (Glory is to Allah).
Al-Bukhari, cf. Al-Asqalani, Fathul-Bari 6/135.