1 Samuel 10:1 - The Popular Commentary by Paul E. Kretzmann

Then Samuel took a vial, a flask or small jug, of oil, and poured it upon his head, as a mark of consecration to the Lord; for every king was thereby placed in God's service and under His protection, and kissed him and said, Is it not because the Lord hath anointed thee to be captain over His inheritance? The question is really an expression of the most vivid assurance, for Samuel was only the instrument in God's hand, the consecration itself being God's act. Saul was now, before God, the king over His inheritance, over the people who were His property. In further confirmation of this fact, Saul was now given three signs.