كتاب الإمارة
33  
The Book on Government
(30)
Chapter: The virtue of going out in the morning or the evening in the cause of Allah
(30)
باب فَضْلِ الْغَدْوَةِ وَالرَّوْحَةِ فِي سَبِيلِ اللَّهِ ‏‏
Sahih Muslim 1882

It has been narrated on the authority of Abu Huraira that the Messenger of Allah (ﷺ) said:

If some persons of my Umma (were not to undertake the hardships of Jihad), and he (Abu Huraira) then narrated the rest of the hadith and then said: A journey undertaken for jihad in the evening or morning merits a reward better than the world and all that is in it.
حَدَّثَنَا ابْنُ أَبِي عُمَرَ، حَدَّثَنَا مَرْوَانُ بْنُ مُعَاوِيَةَ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ ذَكْوَانَ، بْنِ أَبِي صَالِحٍ عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ لَوْلاَ أَنَّ رِجَالاً مِنْ أُمَّتِي ‏"‏ ‏.‏ وَسَاقَ الْحَدِيثَ وَقَالَ فِيهِ ‏"‏ وَلَرَوْحَةٌ فِي سَبِيلِ اللَّهِ أَوْ غَدْوَةٌ خَيْرٌ مِنَ الدُّنْيَا وَمَا فِيهَا ‏"‏ ‏.‏
Reference : Sahih Muslim 1882
In-book reference : Book 33, Hadith 172
USC-MSA web (English) reference : Book 20, Hadith 4642
  (deprecated numbering scheme)