Man Lā Yaḥḍuruh al-Faqīh

Hadith 487
funeral-prayer
488 - وَ سُئِلَ: مَتَى تَجِبُ اَلصَّلاَةُ عَلَيْهِ قَالَ «إِذَا عَقَلَ اَلصَّلاَةَ وَ كَانَ اِبْنَ سِتِّ سِنِينَ.
Hadith.488 - He was asked : "When does the funeral prayer become obligatory for a child?" Imam (as) replied: "When the child understands the concept of prayer and is six years old."
Source: Shaykh Muḥammad b. ʿAlī al-Ṣaduq