Bukhari

Hadith Commentary:
And it is evident that the commander of the army must have given this reward from the khums (one-fifth share).
Although this action was performed by the commander of the army, it occurred during the time of the Messenger of Allah (sallallahu alayhi wa sallam); he (sallallahu alayhi wa sallam) must have heard of it and remained silent regarding it, thus it serves as a proof.

Hadith Commentary:
Imam Bukhari rahimahullah has mentioned this expedition after the (expedition of) Ta’if, whereas the view of other scholars of Maghazi is that this detachment was dispatched by the Prophet sallallahu alayhi wa sallam before setting out for the conquest of Makkah.
Its commander was Abu Qatadah radi Allahu anhu.
There were only twenty-five men in it, who, in confrontation with Ghatafan, obtained two hundred camels and two thousand goats.
(Fath al-Bari: 8/70)

Takhrij al-Hadith: [وأخرجه البخاري 3134، ومسلم 35/1749، من حديث مالك به]
Jurisprudential Points:
➊ If the Commander of the Faithful or his appointed deputy distributes the spoils of war (mal-e-ghanīmah) or a portion thereof among his army after extracting the khums (one-fifth), then it is lawful (halal) for the members of the army.
➋ If there is a threat of attack from the disbelievers, then by the order of the Caliph, a preemptive jihad (jihād al-taqdīm) may be undertaken.
➌ The wealth acquired from the disbelievers during a state of war is called spoils of war (mal-e-ghanīmah).
➍ Sa‘id ibn al-Musayyib rahimahullah used to say: When people would distribute the spoils of war on the battlefield, they would consider one camel equivalent to ten goats. [الموطأ 2/450 ح1001، وسنده صحيح]