Abu Dawud Book 8, Hadith Number 2744.
Narated By Habib ibn Maslamah al-Fihri : Makhul said: I was the slave of a woman of Banu Hudhayl; afterwards she emancipated me. I did not leave Egypt until I had acquired all the knowledge that seemed to me to exist there.
I then came to al-Hijaz and I did not leave it until I had acquired all the knowledge that seemed to be available.
Then I came to al-Iraq, and I did not leave it until I had acquired all the knowledge that seemed to be available.
I then came to Syria, and besieged it. I asked everyone about giving rewards from the booty. I did not find anyone who could tell me anything about it.
I then met an old man called Ziyad ibn Jariyah at-Tamimi. I asked him: Have you heard anything about giving rewards from the booty? He replied: Yes. I heard Maslamah al-Fihri say: I was present with the Prophet (PBUH).
He gave a quarter of the spoils on the outward journey and a third on the return journey.