Samuel took a container of oil and poured it on Saul’s head to anointed him to be the leader of his people Israel. “In the Law this anointing signified the gifts of the Holy Spirit, which were necessary for those who would rule” (Geneva Study Bible). There were two kinds of anointing- a ceremonial and official. A ceremonial anointing involved pouring olive oil on the head or body. An official anointing was the same except it was symbolic of bring set a part for religious service.
“To confirm the consecration of Saul as king over Israel, which had been effected through the anointing, Samuel gave him three more signs which would occur on his journey home, and would be a pledge ti him that Jehovah would accompany his undertakings with his divine help, and practically accredit him as his anointed” (Keil and Delitzsch Biblical Commentary on the Old Testament). Samuel told Saul to do whatever his hands finds to do when the signs were fulfilled because God was with him.
“As Saul turned to leave Samuel, God changed Saul’s heart, and all these signs were filled that day” (1 Samuel 10:9 NIV). Yet, his attributes and behavior did not show a true spiritual life. He struggled with sin and wanted to worship God. God worked by the Holy Spirit in Saul’s life to cause him to use the prophetic gift. This was not a vocation for Saul, but an opportunity. “Yet let not an outward show of devotion, and sudden change for the present, be too much relied on; Saul among the prophets was Saul still” (Matthew Henry). Prophecy is given by God; it does not come through inheritance.
Samuel told the peole of Israel to assembled at Mizpah, which was where they had gathered for spiritual revival before their victory over the Philistines. “But before preceeding to the election itself, Samuel once more charged the people with their sin in rejecting Gid, who had brought them out of Egypt, and delivered them out of the hand of all their oppressors, by their demand for a king, that he might show them how dangerous was they way which they were taking now, and how bitterly they would perhaps repent of what they had now desired” (O.v. Gerlach).
The choice of Saul as Israel’s first king was made by casting lots, which was used to determine God’s will. “Samuel explained the laws concerning kingship to the people. He wrote the laws on a scroll, which he placed in front of the Lord. Then Samuel sent the people back to their homes” (1 Samuel 10:25 GWT). There were some who questioned Saul’s ability to lead and refuse to honor him with gifts. But Saul kept silent to avoid disputing.
Proverbs 16:33 (NIV) The lot is cast into the lap, but its every decision is from the LORD.