Reference for Zevachim 98:6

אמר רבינא איצטריך אי אקשיה לחטאת ולא אקשיה לעולה הוה אמינא חטאת מהיכן למדה מעולה דבר הלמד בהיקש חוזר ומלמד בהיקש

Mar Zutra the son of R'Mari said to Rabina: Then let it be likened to a burnt-offering and not likened to a sin-offering? - Then I would say, [that elsewhere] that which is learnt through a hekkesh in turn teaches through a hekkesh;<span class="x" onmousemove="('comment',' I.e., there would be nothing in this text to shew the contrary.');">¹⁰</span> and if you object, Then let it be likened to a sin-offering,<span class="x" onmousemove="('comment',' Which would positively prove it.');">¹¹</span>

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