Reference for Arakhin 18:20

דל ירחא לבהדי ירחא דמשכחת לה ביום הנף

Rabina demurred: But there are days made of hours,<span class="x" onmousemove="('comment',' Granted that 'Others' go by the order of the new moons, yet it happens that in a simple (not prolonged) year, five days may intervene between one Passover and the other. For the forty minutes above twenty-nine days and twelve hours, between one moon and the other, make in one year an additional eight hours, in three years an additional day.');">¹²</span>

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