“I once asked abu Ja‘far (a.s.), about the case of one of our men who bought from the sultan of the camels of charity and sheep of charity and he knew that they took more than what is rightly due on them. He (the Imam) said, ‘Camels and sheep are just like wheat and barley and other goods. It is not unlawful unless he recognizes the very substance of what is unlawful.’ It was asked, ‘What do you say about the charity collectors who come to us, collect the charity from our sheep, then we ask them to sell them to us and they sell them? What do you say about buying from them? He (the Imam) said, ‘If he has taken them away, then it is not unlawful.’ It was asked, ‘What do you say about wheat and barley which the charity collector takes from us with his measurement and keeps it to one side: if we buy such foodstuff from him?’ He (the Imam) said, ‘If he has taken possession with a certain measurement, then it is not unlawful to buy from him without measuring.”