Reference for Keritot 28:21

וכן אתה מוצא בבת בנו ובבת בן בנו עד סוף כל הדורות

If one has committed a sin which involves two death penalties,<span class="x" onmousemove="('comment',' I.e., if the woman was forbidden to him because of their twofold inter-relation. As to the scale of the various forms of execution, cf. Sanh. 49b.');">¹²</span>

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