Ibn ‘Abbas said that the people of pre-Islamic times used to eat some things and leave others alone, considering them unclean. Then God sent His Prophet and sent down His Book, marking some things lawful and others unlawful; so what He made lawful is lawful, what He made unlawful is unlawful, and what He said nothing about is allowable. And he recited, ''Say, I do not find in what is revealed to me anything forbidden to him who eats it, except carrion or blood..." 1
1. Qur'an, vi, 145.
Zahir al-Aslami said he was kindling fire under pots which contained asses' flesh when God's messenger's crier made an announcement to the effect that God's messenger prohibited asses' flesh to the people.
Abu Sa'id al-Khudri reported the Prophet as saying, "When a fly alights on food plunge it in, for one of its wings contains poison and the other a cure, and it puts the poison first and the cure second."