Mishkat al-Masabih, hadith 2319

وَعَنْهُ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ إِذَا كَانَ فِي سَفَرٍ وَأَسْحَرَ يَقُولُ: «سمع سامع يحمد الله وَحسن بلائه علينا وربنا صَاحِبْنَا وَأَفْضِلْ عَلَيْنَا عَائِذًا بِاللَّهِ مِنَ النَّارِ» . رَوَاهُ مُسلم

He said that when the Prophet was on a journey he would say at daybreak, "Let a hearer hear beginning with praise of God and His good favour towards us. Our Lord, accompany us and show favour to us who are seeking refuge in God from hell." Muslim transmitted it.