1,156. Where Shofar Could Be Blown on Shabbos

Hilchos Shofar, Succah v’Lulav 2:8

When the Sages ruled that we may not blow shofar on Shabbos, they only applied the rule to cities that lacked a court. When the Temple was standing and the Sanhedrin sat in Jerusalem, everyone would blow shofar in Jerusalem as long as the court met there. This was true not just of the residents of Jerusalem; it also applied to any city that was within the Shabbos boundary of Jerusalem as long as they could: see Jerusalem (which excludes those in a valley); hear the shofar being blown in Jerusalem (which excludes those on mountains); or travel to Jerusalem (which excludes those blocked from the city by a valley). In the other cities, they would not blow shofar on Shabbos.

Hilchos Shofar, Succah v’Lulav 2:9

Nowadays, since the Temple is destroyed, wherever there is a permanently-established court whose judges received the original ordination that can only be conveyed in Israel, the shofar is blown on Shabbos. Further, shofar is only blown on Shabbos in a court that has sanctified the new moon. Shofar is not blown in other courts even if their judges received the original ordination. Finally, shofar is only blown in the presence of the Sanhedrin. Shofar may be sounded so long as the court remains in session. If they are preparing to rise but have not yet actually risen, shofar may still be blown before them. Outside the court, however, shofar may not be blown. Shofar is permitted to be blown in such circumstances because the court is scrupulous in mitzvos. In the presence of such a court, those who blow shofar will be careful not to carry it in the public domain because the court will educate the people.