Amr bin Shu'ayb relates from his father, from his grandfather (may Allah be pleased with them both), that Shababah, a clan of Fahm, (and he mentioned something similar), and he said: "From every ten skins, one skin." Sufyan bin Abdullah al-Thaqafi (may Allah be pleased with him) says that he used to reserve two valleys for them; so they paid him what they used to pay to the Messenger of Allah (peace and blessings be upon him), and he reserved their two valleys for them.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7461