Question: Making vows for other than Allaah is void. However, is it valid, for instance, to vow a sheep for Shaykh Muhyee Al-Deen or `Abdul-Qaadir Al-Jeelaanee and then give the meat to the poor, claiming that the Shaykh receives the reward and so he blesses whoever made the vow? If not, is it lawful to eat the meat of these vowed sheep? Does this fall under the saying of Allaah, …and that on which Allaah’s Name has not been mentioned while slaughtering, (that which has been slaughtered as a sacrifice for others than Allaah because the vowed animal is Taahir (purified)? Can that Taahir animal be unlawful because of a void vow?
Answer: First of all, vowing and slaughtering are acts of `Ibaadah (worship) that should not be offered to other than Allaah (Exalted be He). Whoever vows or slaughters for other than Allaah commits Shirk (associating others with Allaah in His Divinity or worship)… read more here.