Man Lā Yaḥḍuruh al-Faqīh

Hadith 485
funeral-prayer
486 - وَ رَوَى زُرَارَةُ وَ عُبَيْدُ اَللَّهِ بْنُ عَلِيٍّ اَلْحَلَبِيُّ عَنْ أَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ: أَنَّهُ سُئِلَ عَنِ اَلصَّلاَةِ عَلَى اَلصَّبِيِّ مَتَى يُصَلَّى عَلَيْهِ فَقَالَ «إِذَا عَقَلَ اَلصَّلاَةَ» فَقُلْتُ مَتَى تَجِبُ اَلصَّلاَةُ عَلَيْهِ قَالَ «إِذَا كَانَ اِبْنَ سِتِّ سِنِينَ وَ اَلصِّيَامُ إِذَا أَطَاقَهُ.
Hadith.486 – Zurarah and Ubaidullah ibn Ali Al-Halabi narrated from Imam Jafar ibn Muhammad Al-Sadiq (as) that He was asked about when the funeral prayer should be offered for a child. Imam (as) replied: "When the child understands the concept of prayer." I asked: "At what age does prayer become obligatory for the child?" Imam (as) replied: "When the child reaches six years old, and fasting becomes obligatory when they are capable of it."
Source: Shaykh Muḥammad b. ʿAlī al-Ṣaduq