Supplications to be made at Various Times - Section 2 Mishkat al-Masabih 2438

Arabic hadith text
وَعَنْ أَبِي هُرَيْرَةَ قَالَ: إِنَّ رَجُلًا قَالَ: يَا رَسُولَ اللَّهِ إِنِّي أُرِيدُ أَنْ أُسَافِرَ فَأَوْصِنِي قَالَ: «عَلَيْكَ بِتَقْوَى اللَّهِ وَالتَّكْبِيرِ عَلَى كل شرف» . قَالَ: فَلَمَّا وَلَّى الرَّجُلُ قَالَ: «اللَّهُمَّ اطْوِ لَهُ الْبعد وهون عَلَيْهِ السّفر» . رَوَاهُ التِّرْمِذِيّ
Translation

Abu Huraira told of a man who said, “Messenger of God, I intend to make a journey, so give me an injunction.” He told him to maintain fear of God and say “God is most great” on every rising ground, and when the man turned away he said, “O God, make the distance short for him and make the journey easy for him.” Tirmidhi transmitted it.