الكافي- ط الاسلامية, volume 2, page 441

4. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad ibn ‘Isa from Muhammad ibn Sinan from Mu’awiyah ibn Wahab who has said the following: “Once we left for Makka and with us there was an old man, very religious and worshipping but did not know this cause (Shi’a Muslim belief). He would pray full (not in reduced form) on a journey and with him there was the son of his brother, also a Muslim. The old man became ill and I said to the son of his brother, ‘If you introduce this cause to your uncle perhaps Allah may grant him freedom.’ All of them said, ‘Leave the old man alone to die in his condition; he looks just fine.’ The son of his brother did not wait and said, ‘Uncle, people after the Messenger of Allah proselytized (gave up their religion) except a very few people. Ali ibn abu Talib must have been obeyed just like the Messenger of Allah had been obeyed. After the Messenger of Allah it was the right of Ali to be obeyed.’ “The narrator has said that the old man sighed deeply and said, ‘I am upon this (belief),’ and he died. We then went in the presence of Abu ‘Abdillah (a.s.) and Ali ibn al-Sariy narrated the story before Abu ‘Abdillah (a.s.) and he said, ‘He was a man of paradise.’ Ali ibn al-Sariy said, ‘He had no knowledge of this cause except for one Sa’ah there. ’ The Imam said, ‘What else do you want from him. He, by Allah, has entered paradise.’”

Translation: Muhammad Sarwar·Thaqalayn link·The Arabic above is the original.