Reference for Bekhorot 52:52

תלמוד לומר תעשה הוסיף לך הכתוב עשייה אחרת בשורך

in the threshing floors,<span class="x" onmousemove="('comment',' This applies to all the classes mentioned here, to the priests for terumah, to the Levites who receive the first tithes, and to the poor who are the recipients of the poor men's tithing every third year.');">²⁸</span>

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