Reference for Zevachim 98:7

א"ל מר זוטרא בריה דרב מרי לרבינא וניקשיה לעולה ולא ניקשיה לחטאת

[I could reply:] It [Scripture] prefers to liken it to the principal rather than to the secondary.<span class="x" onmousemove="('comment',' The burnt-offering is the principal source of the law, since it is there that the north is specified, whereas the sin-offering is only a secondary source, since it is derived from the former.');">¹²</span> Therefore it likened it to a sin-offering and it likened it to a burnt-offering, thus intimating that that which learnt through a hekkesh does not in turn teach through a hekkesh.

Jastrow