Albert Barnes Commentary 1 Kings 13:32

"For the saying which he cried by the word of Jehovah against the altar in Beth-el, and against all the houses of the high places which are in the cities of Samaria, shall surely come to pass." — 1 Kings 13:32 (ASV)

Against all the houses of the high places - That is, more than the two high places at Dan and Bethel. There were many lesser high places in the land, several of which would likely have been in Israel (1 Kings 3:4).

In the cities of Samaria - The word "Samaria" could not have been used by the old prophet, since in his day the city of Samaria did not yet exist (1 Kings 16:24). The writer of Kings has substituted the prophet's original term with the name by which the country was known in the writer's own time.