Reference for Eruvin 181:8

ושמואל אמר בין עירבו בין שלא עירבו וכן אמר ר' יוחנן מי לחשך בין עירבו ובין שלא עירבו

a scroll of the Law from a courtyard into a roof, from the roof into a courtyard, and from the courtyard into a karpaf in order to read in it.<span class="x" onmousemove="('comment',' From this R. Judah sought to lay down the law for normal times.');">¹⁸</span> They,<span class="x" onmousemove="('comment',' His colleagues at the college.');">¹⁹</span> however, said to him: A time of danger can supply no proof.<span class="x" onmousemove="('comment',' As to what is permitted in normal times.');">²⁰</span>

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