Mukhtasar Bukhari (Abridged) 954 — Children fasting

Rabi’ bint Mu’awwiz (may Allah be pleased with her) says that the Prophet (peace and blessings of Allah be upon him) sent a message to the settlements of the Ansar on the morning of ‘Ashura: “Whoever began the morning without fasting should neither eat nor drink for the rest of the day. And whoever began the morning in a state of fasting should complete his fast.” Rabi’ (may Allah be pleased with her) says that after that, we would regularly fast on ‘Ashura and make our children fast as well, and we would make toys out of cotton for them, so that when any of them cried for food, we would give him that toy until the time of iftar came.