cap said:
The concept may not appear in the OT, but it’s not a contradiction either. Obi-Wan once believed that Anakin was the Chosen One. By the time of the OT, he no longer believes that. Why would he mention that he once did?

Pretty sure it’s brought up in Rebels when Obi-Wan kills Maul, he confirms that he believes Luke is the Chosen One. Now obviously by Word of God, Anakin is really it, but it makes sense why Obi-Wan would think that by the OT since, from his perspective, Anakin betrayed what the prophecy meant.

JEDIT: https://youtu.be/shHkJVHFFAk