It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Do not call your dead impure, for a Muslim is not impure, whether alive or dead." (b) It has been reported from Ibn Uyaynah through another gharib (unusual) chain, and what is known is that it is mawquf (his own statement).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1463