The Israelites saw that Gideon was acting like a king. He judged and punished cities for offending him and refusing to help him. He hacked down enemy kings out of personal vengeance (Judges 8:21). So it comes as no surprise here that the men of Israel say to him, Rule over us, you and your son and your grandson also, for you have saved us from the hand of Midian.
To be sure, they carefully avoid using the word king.
But that is clearly the office they have in mind with this offer, since they speak of a hereditary office and his response in Judges 8:23. “This interpretation finds support in the reminiscences of this text in 1 Samuel 8:1–22, where the account of the Israelites’ request to Samuel for a king is recounted. The narrator may have avoided the term [king] because the issue in Gideon’s statement is not a title or an office but performance, which from beginning to end belongs to God."1
22 Then the men of Israel said to Gideon, “Rule over us, you and your son and your grandson also, for you have saved us from the hand of Midian.”