Muwatta Malik 1555
موطأ مالك#1555Da'ifThese are the words of a Companion, not of the Prophet ﷺ. The chain is graded on its own terms.
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، أَنَّ مَرْوَانَ بْنَ الْحَكَمِ، كَتَبَ إِلَى مُعَاوِيَةَ بْنِ أَبِي سُفْيَانَ أَنَّهُ أُتِيَ بِمَجْنُونٍ قَتَلَ رَجُلاً . فَكَتَبَ إِلَيْهِ مُعَاوِيَةُ أَنِ اعْقِلْهُ وَلاَ تُقِدْ مِنْهُ فَإِنَّهُ لَيْسَ عَلَى مَجْنُونٍ قَوَدٌ . قَالَ مَالِكٌ فِي الْكَبِيرِ وَالصَّغِيرِ إِذَا قَتَلاَ رَجُلاً جَمِيعًا عَمْدًا أَنَّ عَلَى الْكَبِيرِ أَنْ يُقْتَلَ وَعَلَى الصَّغِيرِ نِصْفُ الدِّيَةِ . قَالَ مَالِكٌ وَكَذَلِكَ الْحُرُّ وَالْعَبْدُ يَقْتُلاَنِ الْعَبْدَ فَيُقْتَلُ الْعَبْدُ وَيَكُونُ عَلَى الْحُرِّ نِصْفُ قِيمَتِهِ .
Yahya related to me from Malik from Yahya ibn Said that Marwan ibn al-Hakam wrote to Muawiya ibn Abi Sufyan that a madman was brought to him who had killed a man. Muawiya wrote to him, "Tie him up and do not inflict any retaliation on him. There is no retaliation against a madman." Malik said about an adult and a child when they murder a man together, "The adult is killed and the child pays half the full blood-money." Malik said, "It is like that with a freeman and a slave when they murder a slave. The slave is killed and the freeman pays half of his value
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 43:4