Reference for Bekhorot 100:1

רב יהודה אמר רב אסי

Rab Judah reported in the name of R'Assi: Every silver coinage mentioned in the Pentateuch without any qualification means in Tyrian currency;<span class="x" onmousemove="('comment',' And where the Scripture says shekel it means a Tyrian sela', which has four denars, and where it does not say shekel but kesef (silver coinage) it means a Tyrian denar. In B.K. ');">¹</span>

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