רבי עקיבא סבר: אמרינן קלוטה כמי שהונחה דמיא, ורבנן סברי: לא אמרינן קלוטה כמי שהונחה דמיא
Rabbi Akiva holds [that] we say [that] an object in airspace is considered at rest. And the Rabbis hold [that] we do not say [that] an object in airspace is considered at rest.
WHEN DOES “KELUTAH” WORK?
According to Rebbi Akiva, an object that passes through the air of Reshut ha’Rabim (public domain) is considered as though it has rested there (“Kelutah k’Mi she’Hunchah Dami”). The Rishonim ask that according to Rebbi Akiva, how can one ever be liable for throwing an object four Amot through the airspace of a Reshut ha’Rabim, if the object is considered resting at every point through which it travels?
(a) TOSFOS (5b, DH b’Shleima) answers that it is a Halachah l’Moshe mi’Sinai that “Kelutah k’Mi she’Hunchah Dami” does not take effect when an object is thrown four Amot in Reshut ha’Rabim (as the Gemara says (96b), carrying or throwing an object four Amot in Reshut ha’Rabim is derived from a Halachah l’Moshe mi’Sinai).
(b) The RAMBAN (5b) and TOSFOT YESHANIM (4b) explain that the concept of “Kelutah” applies only l’Chumra, to make a person liable, but not l’Kula, to exempt a person from transgressing.
(c) The Ramban and Rishonim offer another answer. The concept of “Kelutah” applies only after the object has entered a new Reshut. Within the same Reshut, though (such as Reshut ha’Rabim), “Kelutah” does not apply.