1. It is forbidden by Rabbinic decree to eat matzah on Erev Pesach, beginning from dawn of the day before Pesach. The purpose of this is to make the eating of the matzah at night clearly for the sake of the mitzvah. Likewise, it is forbidden to eat even “puffed” or “folded” matzah on Erev Pesach though we are strict about such matzos and we treat them as chametz and do not eat them on Pesach. Some have a custom to not eat any matzah starting from Rosh Chodesh Nissan (Shulchan Aruch and Mishnah Berurah 471).
2. It is also forbidden to feed matzah to young children on Erev Pesach, unless they are so young that they will not understand anything that will be recounted to them at night about the Exodus from Egypt (ibid.).
