The Gemarah goes back and forth on sources for Aseh Docheh Lo Sa'aseh - and sometimes citing sources where the other is true and why we don't learn from those sources.

I am wondering why the Gemara (and the meforshim that I saw) seem to be silent and not to bring from the Gemarah in ????? ?? that says ??? Aseh Docheh Lo Sa'aseh ???÷?? which seems to be a rule that the Gemara learns out from the fact that one in prohibited from eating the marrow from the bones of the Korbon Pesach - and other areas where one is not permitted to eat the meat of Korbonos. Why is it not asked that we should learn from here that Aseh is not Docheh Lo Sa'aseh. I couldn't find anyplace that this question is raised.

Thank you so much for providing a forum for questions such as these.

Naftoli Willner, Baltimore, United States