Abu Hurairah reported,
The Prophet ﷺ said that a man had never done a single good deed in his life apart from affirming the oneness of Allah. When death came upon him, he told his family, "When I die, take me and burn me until you have reduced me to charcoal, then grind me up, then scatter me over the sea on a windy day."They did exactly that with him. And then there he was, held in the grasp of Allah.Allah 
asked him, "What led you to do what you did?"He replied, "Fear of You."So Allah forgave him.
Ahmad 3786
Sahihقال يحيى حدثنا حماد عن ثابت عن أبي رافع عن أبي هريرة رضي الله عنه عن النبي ﷺ بمثله
Its isnad is sahih. Abu Rafi is Nufay bin Rafi, the goldsmith, a senior tabii who was trustworthy and among the great tabiin, mentioned previously at 129. The hadith belongs to the musnad of Abu Hurairah, mentioned here following the one before it, with the same meaning. It also appears in Majma al-Zawaid 10:194, attributed there to the Musnad, where its isnad was graded sahih.