110:14 It’s appropriate for every G-d-fearing person to personally supervise the baking of his matzah, letting the workers know to make it quickly and with careful attention to detail. This was done by the early Sages and it’s still done in our time.
110:15 The matzos that a person uses to fulfill the obligation to eat matzah on the first two nights of Pesach are called “the matzos of the mizvah.” These should be made specifically for the mitzvah by an adult Jew who understands what he or she is doing. “Adult” means at least thirteen years and a day old for a male or a twelve years and a day old for a female. (Some people mistakenly let a child add the water to the flour; this is part of the kneading process and is not to be done by a minor – Mishnah Brurah 460:4.) At each stage of the process, even when drawing the water, the worker should say “for the sake of the mitzvah.” (One need not say it before each matzah; he can specify that his work for the day is all for the sake of the mitzvah – Bi’ur Halacha 460:1 s.v. v’katan.) All the laws we have discussed regarding baking matzah are based upon our practice to bake everything before Pesach. In a case of need, when we bake on Pesach, there are additional restrictions beyond those we have mentioned. Similarly, those who have the practice to bake the matzos for the mizvah on the eve of Pesach after midday must exercise additional caution.