Musnad Abu Ya'la al-Mawsili 1:123

Abu al-Rabi’ narrated to us, Hammad narrated to us, he said: I heard Ayyub, ‘Abd al-Rahman al-Sarraj, and ‘Ubayd Allah ibn ‘Umar narrating it from Nafi’, that he read the letter of ‘Umar ibn al-Khattab: That there is nothing [due] in less than five camels. When they reach five, there is one sheep in them, up to nine. When they are ten, there are two sheep, up to fourteen. When they reach fifteen, there are three [sheep] in them, up to nineteen. When they reach twenty, there are four, up to twenty-four. When they reach twenty-five, there is a *bint makhad* (a one-year-old female camel) in them, up to thirty-five. If they increase, there is a *bint labun* (a two-year-old female camel) in them, up to forty-five. If they increase, there is a *hiqqah* (a three-year-old female camel) in them, up to sixty. If they increase, there are two *bint labun* in them, up to ninety. If they increase, there are two *hiqqah* in them, up to one hundred and twenty. If they increase, then in every fifty there is a *hiqqah*, and in every forty there is a *bint labun*. There is nothing [due] in sheep in what is less than forty. When they reach forty, there is one sheep in them, up to one hundred and twenty. If they increase, there are two sheep, up to two hundred. If they increase beyond two hundred, there are three sheep, up to three hundred. If they increase beyond three hundred, then in every hundred there is one sheep.