1 Samuel 9:9 - Matthew Poole's English Annotations on the Holy Bible

Of God; or, a man of God, which signified the same thing. Was called a seer, because he did discern and could discover things secret and unknown to others. And these are the words, either, first, Of some later sacred writer, which, after Samuel's death, inserted this verse. Or, secondly, Of Samuel, who, being probably fifty or sixty years old at the writing of this book, and speaking of the state of things in his first days, might well call it beforetime. Or rather, thirdly, Of Saul's servant, who might be now stricken in years, and might speak this either by his knowledge of what was in his juvenile years, or upon the information of his father or ancestors. And so it is a fit argument to persuade Saul to go to the man of God, that he might show them their way, and where the asses were, because he was likely to inform them; for the prophets were anciently called seers, because they knew and could reveal hidden things. And the meaning is, that anciently they were not vulgarly called prophets, but seers only; whereas now, and afterwards, they were called seers, yet they were more commonly called prophets.