Mishkat al-Masabih 19 Jihad كتاب الجهاد 121

وَعَنْ أَنَسٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «عَلَيْكُمْ بِالدُّلْجَةِ فَإِنَّ الْأَرْضَ تُطوَى بالليلِ» . رَوَاهُ أَبُو دَاوُد

Anas reported God’s Messenger as saying, “Keep to travelling by night, for the earth is traversed [more easily]* by night.” *Literally ‘the earth is folded up.’ The idea is that at night the journey seems shorter. Abu Dawud transmitted it.