Then Samuel took a flask of oil and poured it on Saul's head and kissed him, saying, "Has not the LORD anointed you leader over his inheritance?
When you leave me today, you will meet two men near Rachel's tomb, at Zelzah on the border of Benjamin. They will say to you, 'The donkeys you set out to look for have been found. And now your father has stopped thinking about them and is worried about you. He is asking, "What shall I do about my son?" '
"Then you will go on from there until you reach the great tree of Tabor. Three men going up to God at Bethel will meet you there. One will be carrying three young goats, another three loaves of bread, and another a skin of wine. They will greet you and offer you two loaves of bread, which you will accept from them.
"After that you will go to Gibeah of God, where there is a Philistine outpost. As you approach the town, you will meet a procession of prophets coming down from the high place with lyres, tambourines, flutes and harps being played before them, and they will be prophesying. The Spirit of the LORD will come upon you in power, and you will prophesy with them; and you will be changed into a different person. Once these signs are fulfilled, do whatever your hand finds to do, for God is with you.
"Go down ahead of me to Gilgal. I will surely come down to you to sacrifice burnt offerings and fellowship offerings, but you must wait seven days until I come to you and tell you what you are to do." As Saul turned to leave Samuel, God changed Saul's heart, and all these signs were fulfilled that day.1 Samuel 10:1-9
Finally the times comes for Samuel to anoint Saul. The prophet of God gave Saul specific instructions about where he would find the donkeys he was looking for, food, and the procession of prophets. He knew that Saul would be too excited to worry about food and the donkeys, so he had to be instructed in detail. Samuel even told Saul that he would be changed into a different person after the Spirit of the LORD came upon him.
The key phrase in this passage seems to be that Saul would be a changed person when the Spirit of the LORD came upon him. Granted, not all of us are leaders, but we can certainly learn from Saul: when the Spirit of the LORD comes on us, we should be changed.
That's the challenge we all face, because like D.L. Moody said when someone asked why he asked often to be filled with the Holy Spirit, "Because I leak."
I can relate.