140. hadíth
وَ سَأَلَهُ سَمَاعَةُ: عَنِ اَلصَّبِيِّ مَتَى يَصُومُ قَالَ «إِذَا قَوِيَ عَلَى اَلصِّيَامِ.
Sama'ah asked Imam (a.s) about when a child should begin fasting. Imam (a.s) said: "When he is strong enough to fast."
Man Lā Yaḥḍuruh al-Faqīh
Shaykh Muḥammad b. ʿAlī al-Ṣaduq
Book of Fasting
Chapter on the Age at Which Children Are Required to Observe Fasting
A fordítás angol nyelvű (Bab Ul Qaim Publications), forrás: Thaqalayn.net.