Al-Hakam said: Sayyiduna Umar (may Allah be pleased with him) wrote that after the Prophet (peace and blessings be upon him) no one should lead the prayer sitting; that a child's deliberate act and his mistake are the same, and expiation is due in it; and that any woman who marries her slave is to be flogged with the hadd punishment.
This is munqati' (broken); its narrator is Jabir al-Ju'fi, and it has also been narrated from Sayyiduna Ali (may Allah be pleased with him) with a chain in which there is weakness.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنايات / 16081
Husayn bin Abdullah bin Dumayrah narrates from his father, who narrates from his grandfather, that Sayyiduna Ali (may Allah be pleased with him) said: The deliberate act of a child and the deliberate act of an insane person are also (counted as) a mistake.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنايات / 16082