Performing Salah behind someone who eats from the animals slaughtered on tombstones

A: It is not permissible to eat from animals which are slaughtered at the shrines of the righteous people. The Imam who eats from such offerings should be advised not to eat from them. (Part No. 22; Page No. 335) If he eats from them after the explanation of the ruling, you should not perform Salah behind him because giving offerings is a kind of worship which can not be done except for Allah Alone. It is not permissible to give offerings to the righteous people or any person because 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." Nusuk refers to the sacrifice. Also, Allah (Exalted be He) says, Verily, We have granted you (O Muhammad صلى الله عليه وسلم) Al-Kauthar (a river in Paradise). Therefore turn in prayer to your Lord and sacrifice (to Him only). The Prophet (peace be upon him) said, Allah has cursed the one who slaughters (a sacrifice) to other than Allah… Related by Muslim in his Sahih on the authority of `Aly ibn Abu Talib (may Allah be pleased with him).May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.