Nedarim 80

אלא פרת ביומי תשרי בלבד

except the Euphrates in Tishri.<span class="x" onmousemove="('comment',' Tishri is the seventh month of the Jewish year, generally coinciding with September-October. If a mikweh (ritual bath) is made of collected rain water, it is efficacious only if its water is still, not running or flowing. On the other hand, a well or spring with its water gushing forth from its source is efficacious even when it flows onward. Now, during the whole year, the river may contain more rain water or melted snow than its own natural waters; consequently, it is all considered as rain water, which does not cleanse when in a running state. But in Tishri the rains have ceased, nor is there any melted snow in the river. Then it is like a well or spring, and even though running its water is efficacious for ritual cleansing. Now, according to this, the river's rise is caused mainly by rain. This conflicts with the view that at all times the water from its source is more. ');">¹</span>

אבוה דשמואל עבד להון מקוואות לבנתיה ביומי ניסן ומפצי ביומי תשרי:

Samuel's father made mikwaoth for his daughters in Nisan<span class="x" onmousemove="('comment',' Nisan, the first Jewish month, corresponding to March-April. As the river is then swollen by rain, he did not permit them to take their ritual bath in the running river, but made special enclosed baths for them. ');">²</span>

אמר ר' אמי אמר רב מאי דכתיב (יחזקאל יב, ג) ואתה בן אדם עשה לך כלי גולה זו נר וקערה

and had mats set for them in the days of Tishri.<span class="x" onmousemove="('comment',' In Tishri they performed their ablutions in the river. Now the bed of the river is miry, and should the feet sink into it, the water cannot reach them and the immersion is invalid; he therefore placed mats in the river bed for them to stand on. Ran gives another explanation: He hung up mats on the shore to serve as a screen, For modesty. [Obermeyer op. cit. p. 418: he set up for them tents made of reeds]. On both explanations this story is mentioned here in support of Samuel's second dictum. ');">³</span> R. Ammi said in Rab's name: What is meant by the verse, Therefore, thou son of man, prepare thee stuff for removing?<span class="x" onmousemove="('comment',' Ezek. XII, 3. ');">⁴</span> This is a lamp, plate and