Reference for Shabbat 252:9

לישנא אחרינא כי פליגי בכיסוי תנור מר מדמי ליה לכיסוי קרקע ומר מדמי ליה לכיסוי כלים:

The <i>halachah</i> is as R. Eliezer. R. Amram objected: And from their words we learn that we may close (a skylight], measure [a mikweh], and tie [a temporary knot] on the Sabbath!<span class="x" onmousemove="('comment',' V. Mishnah infra 157a. The reference there is to a cloth that is not fastened and suspended, and yet we may close a skylight with it. ');">⁹</span>

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