4. The fourth prohibited category refers to an animal which is dedicated to anyone other than Allah, that is to say, one which is slaughtered with the invocation of a name other than the name of Allah—for example, the name of an idol. When slaughtering an animal, the Arab polytheists would invoke the names of their idols, such as al-Lat or al-Uzza. Such a practice is a devotional act addressed to someone other than Allah and is a form of worship in which His glorious name is not mentioned. In this case the reason for the prohibition is entirely related to faith: to safeguard the belief in the Oneness of Allah, to purify worship, and to fight shirk and polytheism in whatever form they may be expressed.
Indeed, it is Allah who created man and gave him control over everything on the earth, subjecting the animal to his power and permitting him to take its life for food on the condition that His name be pronounced at the time of slaughter. Pronouncing the name of Allah while slaughtering the animal is a declaration that one is taking the life of this creature by the permission of its Creator, while if one invokes any other name, he has forfeited this permission and must be denied the use of its flesh.