1 Samuel 15:10-31 (HCSB)
Then the word of the Lord came to Samuel, “I regret that I made Saul king, for he has turned away from following Me and has not carried out My instructions.” So Samuel became angry and cried out to the Lord all night.
Early in the morning Samuel got up to confront Saul, but it was reported to Samuel, “Saul went to Carmel where he set up a monument for himself. Then he turned around and went down to Gilgal.” When Samuel came to him, Saul said, “May the Lord bless you. I have carried out the Lord’s instructions.”
Samuel replied, “Then what is this sound of sheep and cattle I hear?”
Saul answered, “The troops brought them from the Amalekites and spared the best sheep and cattle in order to offer a sacrifice to the Lord your God, but the rest we destroyed.”
“Stop!” exclaimed Samuel. “Let me tell you what the Lord said to me last night.”
“Tell me,” he replied.
Samuel continued, “Although you once considered yourself unimportant, have you not become the leader of the tribes of Israel? The Lord anointed you king over Israel and then sent you on a mission and said: ‘Go and completely destroy the sinful Amalekites. Fight against them until you have annihilated them.’ So why didn’t you obey the Lord? Why did you rush on the plunder and do what was evil in the Lord’s sight?”
“But I did obey the Lord!” Saul answered. “I went on the mission the Lord gave me: I brought back Agag, king of Amalek, and I completely destroyed the Amalekites. The troops took sheep and cattle from the plunder—the best of what was set apart for destruction—to sacrifice to the Lord your God at Gilgal.”
Then Samuel said:
Does the Lord take pleasure in burnt offerings and sacrifices as much as in obeying the Lord?
Look: to obey is better than sacrifice, to pay attention is better than the fat of rams. For rebellion is like the sin of divination, and defiance is like wickedness and idolatry. Because you have rejected the word of the Lord, He has rejected you as king.
Saul answered Samuel, “I have sinned. I have transgressed the Lord’s command and your words. Because I was afraid of the people, I obeyed them. Now therefore, please forgive my sin and return with me so I can worship the Lord.”
Samuel replied to Saul, “I will not return with you. Because you rejected the word of the Lord, the Lord has rejected you from being king over Israel.” When Samuel turned to go, Saul grabbed the hem of his robe, and it tore. Samuel said to him, “The Lord has torn the kingship of Israel away from you today and has given it to your neighbor who is better than you. Furthermore, the Eternal One of Israel does not lie or change His mind, for He is not man who changes his mind.”
Saul said, “I have sinned. Please honor me now before the elders of my people and before Israel. Come back with me so I can bow in worship to the Lord your God.” Then Samuel went back, following Saul, and Saul bowed down to the Lord.