It is reported from Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "When a man holds another man so that a third person kills him, the killer will be killed in retaliation and the one who held him will be imprisoned."
The Shaykh said: This narration is not mahfuz (preserved).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنايات / 16029