נר של חנוכה שהניחה למעלה מעשרים אמה — פסולה, כסוכה וכמבוי. ואמר רב כהנא, דרש רב נתן בר מניומי משמיה דרב תנחום: מאי דכתיב ״והבור רק אין בו מים״? ממשמע שנאמר ״והבור רק״ איני יודע שאין בו מים? אלא מה תלמוד לומר ״אין בו מים״ — מים אין בו, אבל נחשים ועקרבים יש בו.
A Hanukkah lamp that one placed above 20 cubits is invalid, just as a sukka whose roofing is more than 20 cubits high, and just as an alleyway whose beam, its symbolic 4th partition in order to place an eiruv, is more than 20 cubits high, are invalid. The reason is the same in all 3 cases: People do not usually raise their heads and see objects at a height above 20 cubits. As there is a requirement to see all of these, they are deemed invalid when placed above that height. And the Talmud cites another statement that Rav Kahana said that Rav Natan bar Manyumi taught in the name of Rav Tanḥum: What is the meaning of the verse that is written with regard to Joseph: “And they took him, and cast him into the pit; and the pit was empty, there was no water in it” (Genesis 37:24)? By inference from that which is stated: And the pit was empty, don’t I know that there was no water in it? Rather, why does the verse say: There was no water in it? The verse comes to emphasize and teach that there was no water in it, but there were snakes and scorpions in it.