It is narrated from Sayyiduna Ali (may Allah be pleased with him): I washed the Messenger of Allah (peace and blessings be upon him), and I began looking for what is usually found with a dead person, but I found nothing, for he (peace and blessings be upon him) was pure both in life and after death.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6627