Reference for Bava Batra 46:7

בעי ר' ירמיה רגלו אחת בתוך חמשים אמה ורגלו אחת חוץ מחמשים אמה מהו ועל דא אפקוהו לרבי ירמיה מבי מדרשא

— Our Mishnah speaks [in the first clause] of a bird which can only hop. since Mar 'Ukba has laid down that a bird which can only hop does not go further than fifty cubits.<span class="x" onmousemove="('comment',' Hence if it is found beyond 50 cubits it must have flown and may have come from 'the biggest anywhere', and therefore belongs to the finder. ');">⁵</span>

Jastrow

Jastrow