It is narrated from Sayyiduna Ali (may Allah be pleased with him) that he said: I came to the Prophet (peace and blessings be upon him) and said: Your uncle, the misguided old man, has died (meaning my father). He (peace and blessings be upon him) said: "Go and bury him, and do not do anything else until you come to me." Then I came to him (peace and blessings be upon him) and told him, and he (peace and blessings be upon him) ordered me, so I performed the ritual bath (ghusl). Then he (peace and blessings be upon him) made supplications for me which I love so much that nothing on the earth could please me more than them.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6666
Sa'id bin Jubayr (may Allah have mercy on him) said: A man came to Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) and said: My father has died as a Christian. He said: "Wash him, shroud him, apply perfume to him, then bury him." Then he recited this verse: "It is not fitting for the Prophet (peace and blessings be upon him) and those who believe to seek forgiveness for the polytheists, even if they are close relatives." [Surah al-Tawbah: 113]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6667