Sayyidah Hafsah bint Abd al-Rahman narrates from Sayyidah Aishah (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) ordered "the fara'ah: one out of every fifty." In the narration of Hajjaj bin Muhammad and others from Ibn Jurayj: one out of every five.
Hammad bin Salamah narrated it from Abdullah bin Uthman bin Khuthaym and said: one sheep out of every fifty sheep.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19340