One ancient version that I don't see mentioned in any of the other threads is a story from the Talmud, so sometime between 200-500 CE, in which Moses wants to know what will happen to the bible God is writing out so carefully, and God takes him to see the 2nd century scholar Rabbi Akiva teaching it. Moses is really confused and doesn't get what they're talking about.
It's not time travel in a time machine, but it is someone going to the future.