From Their God is Too Small: Open Theism and the Undermining of Confidence in God by Bruce Ware:
Two features of 1 Samuel 15:29 deserve brief mention. First, notice how the author links together the ideas of “will not lie” and “[will not] have regret.” Since it is true that God never lies (2 Tim. 2:13; Titus 1:2; Heb. 6:18), and since these ideas are connected in 1 Samuel 15:29, is not “God never lies and never regrets” the most natural way to understand this passage?
Bruce Ware claims the “natural way” to understand the text of Samuel is by importing questionable interpretations of texts written centuries after the passage being examined. It is important to notice this Calvinist mindset. Understanding passages in their textual context is not a primary importance. Forcing the text into some sort of broader systematic theology is the focus. This mindset is so ingrained that they believe it is the “natural way” to understand the text (nevermind that all of Israel did not have the overriding prooftexts for centuries). How did those Israelites read the text? What was their natural understanding. Possibly, like any reader of any text anywhere, they had to look towards the immediate context. That was their natural way to understand the text. And in context of God revoking His eternal plans, Calvinism was the least of their interpretation of the text.