Charles Ellicott Commentary 1 Kings 21:18

"Arise, go down to meet Ahab king of Israel, who dwelleth in Samaria: behold, he is in the vineyard of Naboth, whither he is gone down to take possession of it." — 1 Kings 21:18 (ASV)

Which is in Samaria. —These words are almost meaningless, unless they literally signify that Ahab was then in Samaria, not in Jezreel. To interpret them as simply part of Ahab’s title, or as signifying the country, not the town of Samaria, is to explain them away.