Sunan Ibn Majah, Hadith 2750 ⓘ
It was narrated from Jabir that the Messenger of Allah 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 " .
also referenced under: Book 23, Hadith 2855 (In-Book) & Volume 4, Book 23, Hadith 2750 (DarusSalam)