What does 1 Samuel 15:29 mean?

Samuel is communicating clearly that the Lord's decision to remove Saul from the kingdom is final. It is over (1 Samuel 15:22–26). The prophet has said that the Lord has done it "this day," tearing the kingdom from Saul as Saul has torn Samuel's own robe (1 Samuel 15:28). The earthly fulfillment will take time, but God's favor is no longer on Saul or his rule.

Samuel uses an interesting name for God: the Glory of Israel. He will not change his mind, Samuel says. The Glory of Israel does not lie and he does not have regret. This echoes Numbers 23:19: "God is not man, that he should lie, or a son of man, that he should change his mind."

Reading this passage in English or other translated languages can suggest a contradiction. In two other places in this chapter, the text associates God's "regret" with Saul (1 Samuel 15:11, 35). The key is understanding that Hebrew's small vocabulary means words often have wide meanings. These need context to be fully interpreted. The root term here is nacham, literally meaning "to sigh." In various contexts, it can refer to the angst of making a mistake, or to emotional pain, or to being comforted. While God indicates negative emotions about what his happening, He is still acting according to His plan. Similar expressions are seen elsewhere in Scripture (Genesis 6:6–7; John 11:33–37).

Samuel, however, uses the term in the sense of realizing an error. This, God cannot do, because He cannot make mistakes. The Lord, in some way, feels grief over Saul's fall. But He still intends, as He always did, to remove Saul from the throne. This verse is clear that the Lord does not change His mind about His decisions or declarations. This is related to the way in which God may allow us the freedom to sin, but that sin grieves Him, as does our rejection of Him (Ezekiel 33:11). The Lord made Saul king, and He meant it. He will now remove Saul from being king, and He will stand by that, as well. What God declares will happen. At the same time, God can be grieved by sin and thus "regret" that human sin causes as much harm as did Saul's.