Reference for Chullin 78:49

חזינן אי איניש אלמא הוא דלא מצי מדחי ליה אסור ואי לא א"ל

but if he is not [a powerful man], the Israelite would be able to say to him, [Strike] your head against the mountain!<span class="x" onmousemove="('comment',' Lit., 'behold thy head and the mountain', i.e., 'either take back your zuz or do without it'. This being the case, the animal is permitted to be eaten whether the Israelite actually returns the money to the heathen or provides him with meat.');">²⁹</span>

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