Al-Kāfi - Volume 6 > Intelligence of a Boy and Signs of his Nobility
Hadith #2

عَلِيُّ بْنُ مُحَمَّدِ بْنِ بُنْدَارَ عَنْ أَبِيهِ عَنْ مُحَمَّدِ بْنِ عَلِيٍّ الْهَمَذَانِيِّ عَنْ أَبِي سَعِيدٍ الشَّامِيِّ قَالَ أَخْبَرَنِي صَالِحُ بْنُ عُقْبَةَ قَالَ سَمِعْتُ الْعَبْدَ الصَّالِحَ ( عليه السلام ) يَقُولُ تُسْتَحَبُّ عَرَامَةُ الصَّبِيِّ فِي صِغَرِهِ لِيَكُونَ حَلِيماً فِي كِبَرِهِ ثُمَّ قَالَ مَا يَنْبَغِي أَنْ يَكُونَ إِلَّا هَكَذَا .

2. Ali ibn Muhammad ibn Bandar from his father from Muhammad ibn Ali al-Hamadaniy from abu Sa‘d al-Shamiy who has said that Salih ibn ‘Uqbah narrated to me saying the following: “I heard the virtuous servant of Allah saying, ‘It is preferable to involve a child in difficult tasks when he is small, so he can be forbearing when he grows up.’ He (the Imam) then said, ‘It is not proper to be other than as such.’”