“No invading group or detachment sets out to fight in the cause of Allah and gets its share of the booty and returns safe and sound, but it has been given two-thirds of its reward in this world. On the other hand, no invading group or detachment returns defeated and injured but it will receive its full reward in the Hereafter.” [Muslim]
"عن عبد الله بن عمرو بن العاص -رضي الله عنهما- مرفوعاً: «ما من غازيَةٍ أو سَرِيَّةٍ تغزو فَتَغْنَم وَتَسْلَمُ إلا كانوا قد تَعَجَّلُوا ثُلُثَي أُجُورِهِمْ، ومَا من غَازِيَةٍ أَوْ سَرِيَّةٍ تُخْفِقُ وَتُصَابُ إِلاَّ تم أُجُورُهُمْ». [صحيح.] - [رواه مسلم.]