Chumash lesson: on Devarim 13:20, Hulin 84a. Tannu Rabanan: That which he hunts (kissui hadam) meaning only what he hunts, what of captured or domestic birds? These are included by the word ‘tzed’. So what does ‘that he hunts mean? The Torah hereby teaches you derech eretz: That you should not eat meat without this preparation. Rashi on ‘this preaparation’: as if you needed to hunt, that is is not readily available, iow, don’t eat meat frequently, so as not to become poor.
Tannu Rabanan: “when Hashem broadens your borders”: the Torah taught us derech eretz–that a person should not eat meat except in ‘teavon’ (not a common state?). Should then a person buy from the market and eat? Talmud lomar” and you shall slaugter from your cattle and sheep. Should then he slaughter all his animals, Talmud lomar ” from the cattle and sheep” and not all of them.
The import of the gemara here is there is a problem with frequent, casual meat consumption. In contrast, if one brings a korban shlamim, there is a great deal of meat to eat, and matanos to leviim and to kohanim. The diet of the kohanim certainly included a great deal of meat. The common denominator is there is spirtiual danger in eating meat,and there are means of protection.
. Either you have the kodesh component, or you have the bother of shehitah, melicha, kissui for birds or wild things, the removal of fat and the gid hanasheh. This would seemingly exclude the concept of going to Moishes supermarket to pick up a roast, not that the concept was unknown to chazal.