John Wesley on 1 Samuel 7:15

Samuel judged - For though Saul was king in Samuel's last days, yet Samuel did not cease to be a judge, being so made by God's extraordinary call, which Saul could not destroy; and therefore Samuel did sometimes, upon great occasions, tho' not ordinarily, exercise the office of judge after the beginning of Saul's reign; and the years of the rule of Saul and Samuel are joined together, Acts 13:20,21.