قَالَ اَلصَّادِقُ عَلَيْهِ اَلسَّلاَمُ: «اَلصَّبِيُّ يُؤْخَذُ بِالصِّيَامِ إِذَا بَلَغَ تِسْعَ سِنِينَ عَلَى قَدْرِ مَا يُطِيقُهُ فَإِنْ أَطَاقَ إِلَى اَلظُّهْرِ أَوْ بَعْدَهُ صَامَ إِلَى ذَلِكَ اَلْوَقْتِ فَإِذَا غَلَبَ عَلَيْهِ اَلْجُوعُ أَوِ اَلْعَطَشُ أَفْطَرَ ».
Imam Jafar ibn Muhammad Al-Sadiq (a.s) said: "A child is to be encouraged to fast when they reach nine years of age, according to their capacity. If they can fast until noon or a little beyond, they should do so. However, if hunger or thirst overwhelms them, they may break their fast."