Q 1: In our country, there are some people who visit the graves of Awliya' (pious people) and slaughter sacrificial animals with the intention of vowing for the sake of their dwellers. After that they distribute the meat of these sacrificial animals between the neighbors of the grave or the shrine they have visited.
Is it lawful to eat the meat of a sacrificial animal that is slaughtered for the Waliy
or does this fall under what is mentioned in the saying of Allah (Exalted be He):
Forbidden to you (for food) are: Al-Maitah (the dead animals- cattle- beast not slaughtered), blood, the flesh of swine, and that on which Allâh’s Name has not been mentioned while slaughtering
If the case is as you have mentioned, then it is not permissible to eat this meat because it is considered slaughtered for other than Allah and this is an act of major Shirk (associating others with Allah in His Divinity or worship), for Allah (Exalted be He) says:
Say (O Muhammad صلى الله عليه وسلم): "Verily, my Salât (prayer), my sacrifice, my living, and my dying are for Allâh, the Lord of the ‘Alamîn (mankind, jinn and all that exists).
"He has no partner. And of this I have been commanded, and I am the first of the Muslims."
The Prophet (peace be upon him) also said:
Allah has cursed the one who sacrifices to other than Allah…
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.