Shulchan Aruch: Chapter 594 - A Person who has not Recited Shemoneh Esreh Cannot Fulfill his Obligation by [Listening to] his Fellow

SECTION 594 A Person who has not Recited Shemoneh Esreh Cannot Fulfill his Obligation by [Listening to] his Fellow. (1)

1 With regard to the nine blessings of the Mussaf service of Rosh HaShanah, even a person who is knowledgeable in the prayers can fulfill his obligation by listening to the prayers of the sheliach tzibbur, as stated in sec. 591[:2]. Nevertheless, [this applies only to a sheliach tzibbur reciting a communal prayer]. If there are not nine people responding Amen to a person’s blessings,1 no other person — even someone who is not familiar with the prayers and who does not know how to pray on his own — can fulfill his obligation by [listening to] that person’s prayers.

[This law applies] even in an instance when it is not necessary for [the person listening] to respond Amen [to the blessings being recited]; e.g., [the person praying] had not yet recited the whispered Shemoneh Esreh of Mussaf, and thus he is praying [to fulfill] his own [obligation to recite that prayer], but he is doing so aloud, in order to fulfill the obligation on behalf of the other person who is not familiar with the prayers. Hence, even if no one answered Amen to his blessings, there is no question of a blessing being recited in vain. Nevertheless, if there are not nine people responding Amen to his prayers, these are not considered as communal prayers. And one cannot fulfill his obligation by listening [to a prayer] other than a communal prayer.

[The rationale is that] this was the ordinance instituted [by our Sages] when they ordained communal prayer — that the sheliach tzibbur should repeat the Shemoneh Esreh aloud to fulfill the obligation of a person who is not familiar with the prayers. Thus if one is not reciting a communal prayer, he is unable to fulfill the obligation of another person with his prayer. For prayer is different from the other blessings, with regard to which one may fulfill his obligation by listening and responding Amen. With regard to prayer, by contrast, every individual must ask for mercy, and it is not proper to ask for mercy through an intermediary unless he is a sheliach tzibbur [who represents the congregation].

With regard to the sounding of the shofar, by contrast, one can fulfill his obligation by listening, even if he knows how to sound the shofar himself, and even if he is not in the presence of a congregation that is listening together with him.2