Sunan Ibn Majah
It was narrated from Jabir that the Messenger of Allah (ﷺ) said: “If the child has cired, the (funeral) prayer should be offered for him (if he dies) and he is an heir.”
حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا الرَّبِيعُ بْنُ بَدْرٍ، حَدَّثَنَا أَبُو الزُّبَيْرِ، عَنْ جَابِرٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا اسْتَهَلَّ الصَّبِيُّ صُلِّيَ عَلَيْهِ وَوَرِثَ " .
Grade: Da’if (Darussalam)
Reference