Imam Sadiq (peace be upon him): Abdullah ibn Abi Ya'qub said: I heard Imam Sadiq (peace be upon him) saying: Whoever sows a seed in a piece of land but does not pay the zakat of it and its crop, and cultivates in that land and his crop turns out full of barley, let him know that this is because of the injustice he committed in taking ownership of the land, or because of injustice to the farmer and its labourers, for Allah has said: فَبِظُلْمٍ مِنَ الَّذِینَ هادُوا حَرَّمْنا عَلَیْهِمْ طَیِّباتٍ أُحِلَّتْ لَهُمْ وَ بِصَدِّهِمْ عَنْ سَبِیلِ اللهِ کَثِیراً [Because of the injustice that came from the Jews, and (also) because of their frequent hindering people from the way of Allah, We made unlawful for them a portion of the good things that had been made lawful to them] (Nisa/160), meaning the flesh of camels, and the flesh and fat of cattle and sheep. Thus did Allah reveal it, so recite it in this way. And so it is that Allah does not make anything lawful in the Qur'an after having made it unlawful, and if He makes something lawful He does not make it unlawful. We asked: 'Is this verse: مِنَ الْبَقَرِ وَ الْغَنَمِ حَرَّمْنا عَلَیْهِمْ شُحُومَهُما [of oxen and sheep We made unlawful to them the fat of both] also part of that?' He said: 'Yes.' I asked: 'Then what is this verse: إِلَّا ما حَرَّمَ إِسْرائِیلُ عَلی نَفْسِهِ [except what Israel had forbidden upon himself]?' He said: 'Whenever the Children of Israel used to eat camel's flesh, pain in the flank would afflict them, so they themselves made camel's flesh unlawful upon themselves. This was before the Torah was revealed upon them. But after the Torah was revealed they did not consider it unlawful, yet they still did not eat it.'