Hazrat Jaabir [radhiallaahu anhu] reported that Rasulullah [sallallaahu alayhi wasallam] said: "Flesh which has grown out of unlawful things will not enter Jannah, but hell is more fitting for all flesh which is grown out of that which is unlawful."
Hazrat Saad bin Abi Waqas [radhiallaahu anhu] said, "O Rasulullah [sallallaahu alayhi wasallam] make dua that Allah Ta'ala, makes me of those whose prayers will be answered." Rasulullah [sallallaahu alayhi wasallam] replied: "O Saad keep your food pure and halaal and you will become of those whose prayers are answered. I swear by Him, in whose hand Muhammed[sallallaahu alayhi wasallam]'s life lies, that when a man casts one morsel of Haraam food into his stomach, The righteous deeds of his shall not be accepted for forty days."
Hazrat Abu Bakr [radhiallaahu anhu] reports that Rasulullah [sallallaahu alayhi wasallam] said: "A body which has been nourished by unlawful things shall never enter Jannah."
Then he mentioned (the case of) a man, who, having journeyed far, is dishevelled and dusty and who spreads out his hands to the sky (saying): O' Rabb! O' Rabb! While his food is unlawful, his clothing is unlawful and he is nourished with unlawful things. How can he be answered?
Hazrath Abu Bakr [radhiallaahu anhu] and a soothsayer's food: Hazrath Abu Bakr [radhiallaahu anhu] had a slave who used to give him a portion of his daily income as the master's share. Once he brought him some food and Hazrath Abu Bakr [radhiallaahu anhu] took a morsel out of it. Then the slave remarked: "You always enquire about the source of what I bring to you, but today you have not done so."
He replied: "I was feeling hungry that I failed to do that. Tell me now, how did you come by this food?"
The slave said: "Before I embraced Islam, I practised sooth-saying. During those days I came across some people for whom I practised some of my charms. They promised to pay me for that later on. I happen to pass by those people today, while they were engaged in a marriage ceremony, and they gave me this food."
Hazrath Abu Bakr [radhiallaahu anhu] exclaimed: "Ah! You would have surely killed me?"
Then he tried to vomit the morsel he had swallowed, but could not do so, as his stomach had been quite empty. Somebody suggested to him to take water to his fill and then try to vomit. He sent for a goblet of water and kept on taking water and forcing it out, till the morsel was vomitted out. Somebody remarked: "May Allah have mercy on you! You put yourself to such trouble for one single morsel." To this he made reply: "I would have thrust it out even if I had to lose my life. I have heard the Prophet [sallallaahu alayhi wasallam] saying. 'The flesh that is nourished by haraam food, is destined for the fire of Hell.' I therefore, made haste to vomit this morsel, lest any portion of my body should receive nourishment from it."