A seer — A seeing, discerning, or observing man: for so the Hebrew verb raah is often used. And this suits well with David's mind: Thou art a wise man, and therefore fit to manage this great business, which requires prudence and secrecy.
Related Commentaries of 2 Samuel 15:27
2 Samuel 15:27
27 The king said also unto Zadok the priest, Art not thou a seer? return into the city in peace, and your two sons with you, Ahimaaz thy son, and Jonathan the son of Abiathar.