Imam Makhul (may Allah have mercy on him) says: I was a slave in Egypt belonging to a woman of the tribe of Hudhayl, and she set me free. When I left Egypt, I had absorbed all the knowledge (of hadith) that was there. Then I came to Syria and sifted through its knowledge as well. Everywhere I asked about "nafl" (an extra reward from the spoils), but I found no one who could tell me anything, until I met an elder called Ziyad bin Jariyah al-Tamimi. I asked him: Have you heard anything about nafl? He said: Yes, I heard Habib bin Maslamah al-Fihri (may Allah be pleased with him) say: I was present with the Messenger of Allah (peace and blessings be upon him) when he (peace and blessings be upon him) gave a quarter (1/4) (of the spoils) as nafl at the start of an expedition and a third (1/3) on the return.