Reference for Pesachim 165:14
רב זביד אמר הכא במאי עסקינן כגון
If we say that they contain no marrow, why do they need burning? Hence it is obvious that they contain marrow. Now if you should think [that] the serving of nothar is something substantial, why do the bones of [other] sacrifices not require burning? - Said R'Nahman B'Isaac: The circumstances here are e.g. , if he found them [the bones] scooped out:<span class="x" onmousemove="('comment',' I.e., the bones were already broken and their marrow removed.');"><sup>24</sup></span> [in the case of] the bones of [other] sacrifices which are not subject to the prohibition of breaking a bone, [we assume that] they were scooped out before it<span class="x" onmousemove="('comment',' The plural in the text probably refers to the separate marrows distributed among the bones.');"><sup>25</sup></span> [the marrow] became nothar', Hence they did not serve nothar and do not require burning. [But in the case of] the bones of the Passover-offering which are subject to the prohibition of breaking a bone, we assume that they were scooped out after they became nothar; hence they had served nothar and require to be burnt. R'Zebid said: The circumstances here are e.g. ,