The basic rule that defines what is permissible or forbidden to eat is the Qur'anic verse that says: ‘Say: “In all that has been revealed to me, I do not find anything forbidden to eat, if one wishes to eat thereof, unless it be carrion, or blood poured forth, or the flesh of swine – for all that is unclean – or a sinful offering over which any name other than Allah’s has been invoked. But if one is driven by necessity, neither intending disobedience nor exceeding his bare need, then know that your Lord is Much-Forgiving, Ever-Merciful”’ (6: 145).