BT Er 18a(21) :באר מים חיים דפסיקא ליה קתני מכונסין דלא פסיקא ליה לא קתני‏ : he teaches the case of a well of fresh water for he is certain about it, while he does not teach the case of collected water for he is uncertain about it
See the entire entry for psīq adj. cut off