Reference for Kiddushin 155:21

רבי יוסי סבר מי שנזרעו בישראל רבי שמעון בן יוחי סבר מי שנזרעו בתוליה בישראל

of sin!<span class="x" onmousemove="('comment',' The union of a High Priest and a widow, and the birth of a halal, are all attended by sin. But that is not true of a proselyte.');">²⁹</span> - Do not say, let [the union of] a High Priest with a widow prove it, but say: let a [converted] Egyptian of the first generation prove it.<span class="x" onmousemove="('comment',' There is no element of sin, yet his daughter is unfit, for only the third generation may marry with Jews.');">³⁰</span>

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