Praise be to Allah.
Ibn al-Qayyim (may Allaah have mercy on him) said:
The one who eats something takes on something of its characteristics in his attitude and actions. Just as there is wisdom in what Allaah has created, there is also wisdom in what He has prescribed and commanded (sharee’ah). He has forbidden His slaves to eat unclean things because if they consume them, these things will become a part of them and they will be what they eat. When a person eats, he resembles what he eats, and what he eats becomes essentially a part of him. Hence man is more balanced in his attitude and behaviour than other animals because he is more balanced in what he eats. Eating blood and the flesh of carnivorous wild animals gives a person a wild, devilish character and makes him aggressive towards other people, so sharee’ah wisely forbids eating such foods except when there is an overwhelming reason to do so, such as absolute necessity. Because the Christians eat pork, it gives them a kind of harshness and cruelty. The same applies to those who eat the flesh of carnivores and dogs – they take on the character of these animals. A devilish attitude is an essential attribute of fanged carnivores, which is why they are forbidden as food by sharee’ah. Since camels may display such a devilish attitude, Islam commands those who eat camel meat to counteract it by doing wudoo’. Since a donkey-like attitude is an essential attribute of donkeys, the Messenger of Allaah (peace and blessings of Allaah be upon him) forbade us to eat them. Since blood is the vehicle of the Shaytaan through which he travels, Allaah has absolutely forbidden us to eat blood.
Whoever ponders the wisdom of Allaah in His creation and His commandments, and pays attention to both, will have opened an important door to the knowledge of Allaah and His Names and Attributes.