Slaughter for other than Allah is shirk

Q: The practice of slaughtering sheep to draw near to the shrines of the righteous awliya (close friends of Allah) still exists in my tribe. I have forbidden it, but they have only become more stubborn. I told them: "It is shirk (associating partners with Allah) with Allah." They said: "We worship Allah with true worship, but what is our sin if we visit His awliya and say to Allah in our supplications: 'By the right of Your righteous wali (close friend of Allah) so-and-so, heal us, or remove such-and-such distress from us...'" I said: "Our religion is not a religion of intermediaries." They said: "Leave us to our own affairs."
What solution do you see as suitable for treating these people? What should I do toward them? And how do I combat bid'ah (religious innovation)? And thank you.

A: It is known from the evidence of the Book and the Sunnah that drawing near by slaughtering for other than Allah, whether for the awliya, the jinn, idols, or any other of the created things, is shirk (associating partners with Allah) and from the deeds of the jahiliyyah (the pre-Islamic age of ignorance) and the mushrikin (those who associate partners with Allah). Allah (Glorified and Exalted is He) said: : [Al-An'am: 162]. And al-nasik is slaughter, and He (Glorified and Exalted is He) clarified in this verse that slaughter for other than Allah is shirk (associating partners with Allah) with Allah, just as prayer for other than Allah is.
And He (Mighty and Majestic) said: فَصَلِّ لِرَبِّكَ وَانْحَرْ [Al-Kawthar: 1-2]. Allah (Glorified and Exalted is He) commanded His Prophet in this noble surah to pray to his Lord and slaughter for Him, in contrast to the people of shirk (associating partners with Allah) who prostrate to other than Allah and slaughter for other than Him. And He (Mighty and Majestic) said: And He (Glorified and Exalted is He) said: [Al-Isra: 23]. And the verses in this meaning are many.
And slaughter is from worship, so it must be made sincere for Allah alone. In Sahih Muslim, from the Commander of the Faithful, Ali ibn Abi Talib (may Allah be pleased with him), it is narrated that he said: The Messenger of Allah (peace and blessings be upon him) said: .
As for the statement of the one who says: "I ask Allah by the right of His awliya, or by the status of His awliya, or by the right of the Prophet, or by the status of the Prophet," this is not shirk (associating partners with Allah), but it is bid'ah (religious innovation) according to the majority of the scholars and one of the means to shirk (associating partners with Allah); because du'a' (supplication) is worship, and its manner is from the matters that are based on divine legislation (taqdiriyyah), and it has not been established from our Prophet (peace and blessings be upon him) anything indicating the permissibility or lawfulness of tawassul (seeking nearness to Allah through a means) by the right or status of any of the created beings. So it is not permissible for the Muslim to innovate a tawassul (seeking nearness to Allah through a means) that Allah (Glorified and Exalted is He) has not legislated ; because of the saying of Allah (Glorified and Exalted is He): : [Al-Shura: 21]. And the saying of the Prophet (peace and blessings be upon him): , agreed upon for its authenticity. And in a narration by Muslim, which al-Bukhari suspended in his Sahih with certainty . And the meaning of his saying: is that it is rejected upon its owner and not accepted. So what is obligatory upon the people of Islam is to adhere to what Allah has legislated and to beware of the bid'ah (religious innovation) that people have innovated.
As for the prescribed tawassul (seeking nearness to Allah through a means), it is tawassul (seeking nearness to Allah through a means) by the names of Allah and His attributes, and by His tawhid (the oneness of Allah), and by righteous deeds, and by faith in Allah and His Messenger, and by loving Allah and His Messenger, and the like of these deeds of righteousness and good. And success is from Allah.