Reference for Yevamot 241:17
אמר רב אשי הא דאמרו רבנן מים שאין להם סוף אשתו אסורה הני מילי באיניש דעלמא אבל צורבא מרבנן לא אי דסליק קלא אית ליה ולא היא לא שנא איניש דעלמא ולא שנא צורבא מרבנן דיעבד אין לכתחלה לא
Once a man was drowned in the swamp of Samki, and R. Shila permitted his wife to marry again. Said Rab to Samuel: 'Come, let us place him under the ban'.<span class="x" onmousemove="('comment',' For permitting a married woman to remarry. ');"><sup>30</sup></span> 'Let us first', [the other replied,] 'send to [ask] him [for an explanation]'. On their sending to him the enquiry: '[If a man has fallen into] water which has no [visible] end. is his wife forbidden or permitted [to marry again]'? he sent to them [in reply], 'His wife is forbidden' — 'And [they again enquired] is the swamp of Samki regarded as water that has [a visible] end or as water that has no [visible] end?' — 'It is', he sent them his reply, 'a water that has no [visible] end'. 'Why then did the Master [they asked] act in such a manner?'<span class="x" onmousemove="('comment',' V. p. 855 n. 12. ');"><sup>31</sup></span>