Shulchan Aruch: Chapter 596 - Sounding the Shofar at the Conclusion of the Prayers

SECTION 596 [Sounding the Shofar at the Conclusion of the Prayers.] (1–2)

1 It is customary in some places to sound a long teruah1 which is not [preceded by] a tekiah in order to confound Satan, so that after the prayer service, when [the people] go [to] eat, drink, and rejoice, he will not accuse them [in the Heavenly Court] of failing to stand in awe and dread of the Day of Judgment.

In other places it is customary to repeat the sounding of 30 shofar-blasts, lest some of the congregants did not hear all the blasts in an appropriate and acceptable manner. Thus they will fulfill their obligation with these blasts. It is the custom of some congregations to sound 100 blasts;2 i.e., after the prayers are completed, they sound [many] blasts, so that together with [those sounded before Mussaf and those sounded during Mussaf], there will be 100 in all.3

2 However, once all these blasts have been sounded, the shofar should not be sounded without purpose, for sounding it on a festival is forbidden by Rabbinic decree. This prohibition was waived only for a purpose, e.g., to satisfy women by sounding the shofar for them.4 Similarly, our Sages waived this prohibition for those who follow the custom of sounding the shofar after the prayer service, since they need [to hear] these shofar blasts for reasons known to them.5 [The rationale is] that sounding the shofar is not [prohibited as] a complete shvus,6 but merely as a mundane activity. Nevertheless, to sound the shofar for no reason is to treat the festival irreverently.

Even one who is designated to sound the shofar on the second day [of Rosh HaShanah] may not practice on the first, because we know well7 on which day the month actually begins, and we know that the first day [of Rosh HaShanah] is holy and the second is not. Thus such a person would be sounding the shofar for blasts that he does not require for the festival, but for a weekday.

Needless to say, one should not take a shofar out to the public domain to sound a blast which he does not require that day, for he would be transferring an article from one domain to another for a purpose not associated with the festival. It is, however, permitted to tell a child to sound the shofar so that he becomes trained in sounding it. [This applies] whether or not he has reached the age at which he must be trained to observe the mitzvos. [The child] may sound the shofar the entire day, even after he heard the shofar blasts in the synagogue, because adults are commanded to teach children and train them in the observance of mitzvos.8