A child who is transgressing for the sake of another Jew:[1]
If a child is committing a transgression for the benefit of any other Jew[2] who is already Bar Mitzvah[3]—for example, extinguishing a fire in that Jew’s home when there is no danger to human life—then every Jew[4] is [Rabbinically] obligated to stop the child or reprimand him. This responsibility is not restricted solely to the child’s father or legal guardian.
[1] Admur 343:1 “If he does so on behalf of an adult, one must protest and stop him, by rabbinic law, as explained in סימן של״ד.”; Admur 334:26 in parentheses; Beis Yosef 334; Rosh 1:1; Rabbeinu Yerucham 1:13; Piskeiy Teshvuos 343:13
[2] Admur 343:1 “Bishvil Gadol”; 334:26 “on behalf of his father (or another Jew)”; M”B 334:65 in name of P”M; Ketzos Hashulchan 147 footnote 11
Father versus other person: So rules also Admur in 334:26 that if the child is going to extinguish the fire even on behalf of a person other than his father, he must be reprimanded. Vetzaruch Iyun why Admur in 334:26 stated this addition (another person) in parentheses. To note however that in the Gemara [Yevamos 104a] explains that the reason the child must be reprimanded is because he is doing so on behalf of his father, and thus perhaps here Admur novelizes that even when done on behalf of others he must be reprimanded. [Ketzos Hashulchan 147 footnote 11] This is also explicitly implied in Rashi there which equates this case to the case brought earlier in the Gemara regarding having children carry keys in a public domain on behalf of another person, of which there it was allowed because they were not doing so on behalf of that person. Nevertheless, tzaruch Iyun why the need to place this addition in parentheses. The Mishneh Berurah [334:65] rules in the name of the Peri Megadim as above that the child is to be reprimanded even when he goes to extinguish another person’s fire.
[3] See Chanoch Lanaar 7:3 in name of Sefer Malei Haroim that if a child is doing so on behalf of another child he does not need to be protested. So is also implied from Admur ibid which states “Bishvil Gadol”
[4] See Admur 343:2 [This obligation to reprimand and correct improper behavior is not limited to the Beit Din, even though they are the primary subject discussed in this halacha. Rather, this obligation applies to every individual. This is made explicit by the wording in the beginning of the next halacha, where Admur states that all of the above applies when dealing with “other people”, clearly indicating that the responsibility is not confined to judicial authorities alone.]
