Ibn Awn (may Allah have mercy on him) says: I asked Muhammad (may Allah have mercy on him) about the share of the Prophet (peace and blessings be upon him) and al-safi. He said: "A share was allotted to him (peace and blessings be upon him) along with the Muslims even if he was not present, and for al-safi, one head was taken for him from the khumus (one-fifth) before anything else."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الفيء والغنيمة / 12752