The Prophet ﷺ sent word on the morning of Ashura to the villages of the Ansar, "Whoever has eaten today should complete the rest of his day, and whoever has been fasting should continue his fast."She said, "We used to fast it afterwards and have our young children fast as well. We would make them toys out of ihn, and whenever one of them cried for food, we would give him the toy until it was time to break the fast."He explained that ihn means wool.
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 ذلك حتى يكون عند الإفطار. قال العهن: الصوف.
Bukhari related it in the Book of Fasting (1960), and Muslim in the Book of Fasting (1136), both through Bishr bin Mufaddal bin Lahiq, who said, Khalid bin Zakwan narrated to us, from Rabee bint Muawwidh, with the same chain. The wording is Bukhari's.