Spoilers for Game of Thrones season 6 below.

Jon Snow's already come back from the dead, but if you're looking for more signs that he's truly the Prince That Was Promised/Azor Ahai reborn, a redditor named hatchman88 is pointing out a detail from the season six finale that has hundreds of redditors upvoting their approval. It's all based on this image:

Focus on the hilt.
Focus on the hilt.

Before running up the Tower of Joy, Ned took the sword "Dawn" from a dying member of the Kingsguard, Ser Arthur Dayne. He then leans it on what you have to assume is the bed where Lyanna Stark just gave birth to Jon Snow. This makes for a perfect connection to a prophecy about Westeros's promised savior.