The previous narration from Sayyiduna Umar (may Allah be pleased with him).
Imam al-Shafi'i (may Allah have mercy on him) said: This clarifies our statement that the prayer is not to be offered over them. I hope that he (peace and blessings be upon him) was forbidden from praying over them because whoever he (peace and blessings be upon him) prays over is forgiven, and there is no forgiveness for one who persists in polytheism. Therefore he (peace and blessings be upon him) was forbidden from praying over such a person, but the Prophet (peace and blessings be upon him) did not forbid the Muslims. The Muslims used to pray over them. Hudhayfah, Umar and Abu Bakr (may Allah be pleased with them) all used to pray. Whenever a funeral was placed before Sayyiduna Umar (may Allah be pleased with him), he would look towards Sayyiduna Hudhayfah (may Allah be pleased with him). If he declined, he would not lead the prayer; if he stood with him, he would lead it. Neither Abu Bakr (may Allah be pleased with him) nor Uthman (may Allah be pleased with him) forbade the Muslims from praying over them, nor is there anything of the sort among the rulings of Islam.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب المرتد / 16843