Abu Huraira reported: When the soul of a believer would go out (of his body) it would be received bv two angels who would take it to the sky. Hammad (one of the narrators in the chain of transmitters) mentioned the sweetness of its odour, (and further said) that the dwellers of the sky say: Here comes the pious soul from the side of the earth Let there be blessings of Allah upon the body in which it resides. And it is carried (by the angels) to its Lord, the Exalted and Glorious. He would say: Take it to its destined end. And if he is a nonbeliever and as it (the soul) leaves the body-Hammad made a mention of its foul smell and of its being cursed-the dwellers of the sky say: There comes a dirty soul from the side of the earth, and it would be said: Take it to its destined end. Abu Huraira reported that Allah’s Messenger (peace be upon him) put a thin cloth which was with him upon his nose while making a mention (of the foul smell) of the soul of a non-believer.
Sahih Muslim, Book 53, Hadith 90