Reference for Bava Metzia 105:5

וניתי מעשר דאית ליה ונצטרפינהו דאורייתא ודרבנן לא מצטרפי

because it was distinctly taught: The second tithe is neutralized by a greater quantity [than itself]. And of which second tithe was this said? Of a tithe which is not worth a <i>perutah</i><span class="x" onmousemove="('comment',' V, n. 2. ');">¹³</span> or which has once entered Jerusalem and gone forth again.<span class="x" onmousemove="('comment',' This is explained below. ');">¹⁴</span> But if Hezekiah's ruling is correct, let Hezekiah's [remedy] be employed by redeeming it with the earlier money!<span class="x" onmousemove="('comment',' This is a repetition, with a little more explanatory detail, of the difficulty already raised. ');">¹⁵</span>

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