Reference for Kiddushin 47:6

תנא יוצא בשן ועין וראשי אברים שאינן חוזרים בשלמא שן ועין כתיבי אלא ראשי אברים מנלן דומיא דשן ועין מה שן ועין מומין שבגלוי ואינן חוזרין אף כל מומין שבגלוי ואינן חוזרין

Now, as for [the loss of] his tooth or eye, it is well: these are written.<span class="x" onmousemove="('comment',' Ex. XXI, 26f.');">¹²</span> But how do we know [the loss of] the projecting limbs? - By analogy with tooth and eye: just as these are patent blemishes, and do not return, so [is he freed for the loss of] all [limbs which are] patent blemishes and do not return. But let us say that 'tooth' and 'eye' are two laws<span class="x" onmousemove="('comment',' Lit., 'verses'.');">¹³</span>

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