Reference for Chullin 201:8
(בראשית לב, לג) על כן לא יאכלו בני ישראל את גיד הנשה מי שגידו אסור ובשרו מותר יצתה זו שגידו אסור ובשרו אסור
The Sages, however, agree with R'Meir that if a person ate the sciatic nerve of a burnt-offering or of an ox that was condemned to be stoned he would have incurred guilt twice.<span class="x" onmousemove="('comment',' The prohibition of a burnt-offering or of an ox condemned to be stoned (for having killed a human being, cf. Ex. XXI, 28) can be superimposed upon the existing prohibition of the sciatic nerve, for in the first place it is more comprehensive than the existing prohibition in that it applies to every part of the animal, whereas the existing prohibition applied only to the nerve, and secondly, it imposes a graver restriction, for now the vtbvc ruxt sciatic nerve of the animal is forbidden for all purposes () whereas before it was only forbidden to be eaten.');"><sup>7</sup></span>