Sahih Muslim 4565
The Book of Jihad and Expeditions
وَحَدَّثَنَا عَبْدُ الْمَلِكِ بْنُ شُعَيْبِ بْنِ اللَّيْثِ، حَدَّثَنِي أَبِي، عَنْ جَدِّي، قَالَ حَدَّثَنِي عُقَيْلُ، بْنُ خَالِدٍ عَنِ ابْنِ شِهَابٍ، عَنْ سَالِمٍ، عَنْ عَبْدِ اللَّهِ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَدْ كَانَ يُنَفِّلُ بَعْضَ مَنْ يَبْعَثُ مِنَ السَّرَايَا لأَنْفُسِهِمْ خَاصَّةً سِوَى قَسْمِ عَامَّةِ الْجَيْشِ وَالْخُمْسُ فِي ذَلِكَ وَاجِبٌ كُلِّهِ .
It has been narrated on the authority of Abdullah b. 'Umar that the Messenger of Allah (ﷺ) used to give (from the spoils of war) to small troops seat on expeditions something more than the due share of each fighter in a large force. And Khums (one-fifth of the total spoils) was to be reserved (for Allah and His Apostle) in all cases
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.