Sahih Muslim , Book 33, Hadith 172 (In-Book) ⓘ
It has been narrated on the authority of Abu Huraira that the Messenger of Allah 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 " .
also referenced under: Hadith 1882 (Reference) & Book 20, Hadith 4642 (USC-MSA)