What happended when Saul took vengeance on Amalek?

But Saul and the people spared Agag and the best of the sheep, the oxen, the fatlings, the lambs, and all that was good, and were unwilling to utterly destroy them. But everything despised and Worthless, that they utterly destroyed
(1 Sam. 15:9).

We come now to one of the pivotal chapters of 1 Samuel. Here, Saul’s true nature is decisively revealed, which leads to his rejection as king and sets the stage for the rise of God’s choice for the throne.

It begins when Samuel comes to Saul for the first time since Saul offered his unlawful sacrifice and Samuel pronounced God’s judgment upon him (13:9–15).

Naturally, he comes with a message for Saul from God. Lest Saul in anger reject him before he can speak his message, Samuel begins by reminding Saul that he was the one who anointed Saul as king. He is pointing out that he is God’s instrument, and Saul therefore should listen well to his words. The message is straightforward—God desires to punish the Amalekites for ambushing the Israelites when they came out of Egypt hundreds of years before (Ex. 17; Deut. 25:17–18).

God said at the time that He would one day “ ‘blot out the remembrance of Amalek from under heaven’ ” (Ex. 17:14), and that time has come. He has spared the Amalekites for many years, but “Though He bear long, He will not bear always,”

Matthew Henry notes. Saul is to attack the Amalekites and wipe them out, and he is to “ ‘destroy all that they have.’ ” God is declaring that all the Amalekite people and all their possessions are to be “put under the ban,” or “devoted” to Him. This is holy war. Saul is to be God’s instrument to punish Amalek’s sins, past and present (15:18).

Saul is submissive to God’s word through Samuel. He gathers an army of more than two hundred thousand men and marches south toward Amalek. Before attacking, he warns the Kenites to leave the land of the Amalekites, a return of the kindness the Kenites showed to Israel during its trek from Egypt. This may be a reference to the acts of Moses’ father-in-law, Jethro (Ex. 18; Judg. 1:16).

Thus, God blesses those who have blessed IsraeTl (Gen. 12:3; Num. 24:9). Saul then attacks the Amalekites and triumphs. Everything seems to be going well—until we come to the first word of verse 9: “But.” This changes everything. Now we learn that while Saul has killed almost all of the Amalekites, he has spared their king, Agag.

And while he has destroyed despised and worthless things, he has kept the best of the animals and “all that was good.” In short, he has not followed the precise instructions of God—and God will call him to account for it.God is indeed patient and longsuffering.

And yet, each day His patience comes to an end for many who rebel against Him. Their lives end and they are lost. We are called to tell unbelievers that they are trying the patience of the sovereign God, and that He commands them to repent (Acts 17:30). Whom do you need to speak with today?