1,126. Things a Child May Not Do
165:4 If something isn't inherently prohibited but is only prohibited at a particular time, there is no obligation to train a child in that matter. Therefore, one may give a child something to eat before kiddush even though one is obligated to teach him about kiddush. One may not, however, give him something to eat outside the succah. We're only lenient in the case of kiddush because it is a negative mitzvah not to eat before kiddush. We may not cause a child to violate a positive commandment.
165:5 It's forbidden to give to a child some object to carry outside an eiruv on Shabbos, even if he's under nine years old and even if it's for the purposes of a mitzvah, such as to bring a siddur or a chumash to shul.