Ali ibn Abi Talib (as) was traveling with a non-Muslim. The man asked him where he was headed. Ali (as) responded, “To Kufa”.
Ali (as) and the man traveled a distance together until the man decided to change his path. Ali (as) also followed the man’s path. The man asked Ali, “Weren’t you headed for Kufa?”
Ali (as) confirmed.
The man responded, “Then why did you change your path?”
Ali (as) said, “One of the etiquettes of traveling with a person is to accompany your travel partner for a while upon departure. This is amongst the teachings of our Prophet (PBUH&HP).”
The man replied, “Is that so?”
Ali (as) confirmed. The man continued, “Truly he has gained his followers through his generous manner. I too turn to your faith.”
He then returned with Ali (as) and after getting to know him better, he became Muslim.
Usul-al Kafi, Vol 2, page 670