Reference for Shabbat 269:6

איתמר רב אמר הלכה כת"ק ושמואל אמר הלכה כר"ש בן אלעזר

one may desecrate the Sabbath, but for an eight-months' infant one may not desecrate the Sabbath.<span class="x" onmousemove="('comment',' The Rabbis held that such could not possibly live; hence there is no point in desecrating the Sabbath by circumcising him. ');">⁵</span>

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