Responsum: On the Age of Prayer Leaders

Now, in regard to your inquiry: In a place where only one individual is accustomed to act as the congregational representative [to lead the prayers] in front of the ark, and he is, on occasion, occupied with his work, but there are young lads present who have attained the age of seventeen or eighteen but do not yet have fully grown beards, you have inquired whether they may act as representatives of the congregation, so that they can allow the public to fulfill its obligation [of communal prayer] and not miss out on the prayers.

This is how we perceive it: That which the sages said about one’s beard having to be fully grown was a thing of special merit—and wherever possible, it is preferable to have a man with a fully grown beard rather than a young lad [to lead the prayers]. But most certainly, in a situation where [insistence upon an adult for this] would mean that the Kedushah, and the communal responses “Barukh” or “Yehe” would be unable to be recited, it goes without saying that a youth of seventeen or eighteen years of age may be designated as the representative of the congregation to lead the prayers, but even a lad of thirteen years and a day [may be designated] in circumstances where this is unavoidable, for the sages have stated: This is the general rule: Any person who is not himself obligated to fulfill a religious duty cannot cause the general public to fulfill its religious duty. But from thirteen years of age upward, it is perfectly acceptable, when no viable alternative exists.