Does the Lord Regret?

In 1 Samuel 15, as the eponymous prophet is apprising king Saul of the Lord’s rejection of his house, Samuel says the following in response to Saul’s pleas: “The Lord has torn the kingdom of Israel from you this day and has given it to a neighbor of yours, who is better than you. And also the Glory of Israel will not lie or have regret, for he is not a man, that he should have regret (1 Samuel 15:28-29 ESV).”

After Samuel “hacked Agag to pieces before the Lord” and separated from Saul, we are told that he “grieved over Saul”, which is to be expected. However, we are also told something unexpected: “And the Lord regretted that he had made Saul king over Israel (1 Samuel 15:35 ESV).”