(Mishnah): To obtain the Shofar of Rosh Hashanah, one may not - leave the Techum, clear a collapsed building, climb a tree, ride an animal or swim. One may not cut the Shofar, neither by performing a Rabbinic nor a Torah prohibition.

However, if he wishes to store in it wine or water, he may do so.

One need not prevent children from sounding the Shofar; rather, one may instruct them until they know how to blow.

A Misasek (one who blows Shofar without intent to perform the Mitzvah) and one who hears from a Misasek have not fulfilled their obligation.

(Gemara): (If one may not perform a Rabbinic prohibition, one certainly may not perform a Torah prohibition?!) Rather, the word "Shevus'' must be referring to resting from performing a Torah prohibition in order to obtain a Shofar.

R. Elazar: When the Mishnah referred to a "Misasek'', it refers to an adult blowing a Shofar to teach children on Rosh Hashanah that occurs on Shabbos.

Support (Beraisa): An adult may teach a child to blow, even on Shabbos, and we do not prevent children from blowing on Yom Tov.