Rabi bint Muawiz reported,

The Prophet ﷺ sent word on the morning of Ashura to the villages of the Ansar, "Whoever has begun the day eating should complete the rest of his day, and whoever has begun the day fasting should continue his fast."She said, "We used to fast on this day afterward and have our children fast as well. We would make toys for them out of dyed wool, and whenever one of them cried for food, we would give him the toy to keep him occupied until the time to break the fast."

Bukhari 1960

Sahih

حدثنا مسدد حدثنا بشر بن المفضل حدثنا خالد بن ذكوان

عن الربيع بنت معوذ قالت

أرسل النبي ﷺ غداة عاشوراء إلى قرى الأنصار من أصبح مفطرا فليتم بقية يومه ومن أصبح صائما فليصم قالت فكنا نصومه بعد ونصوم صبياننا ونجعل لهم اللعبة من العهن فإذا بكى أحدهم على الطعام أعطيناه ذاك حتى يكون عند الإفطار

البخاري 1960صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Fasting
Chapter
Fasting of children
Numbering
Darussalam 1960
Bukhari 1960