The term “repented” reflects a figure of speech, common to many languages, known as “anthropopathism” (literally, man feelings). This is an idiom by which divine activity is described
symbolically in terms of human emotion. It is rather similar to the kindred figure, “anthropomorphism” (man form) by which God is described as having physical parts (e.g., eyes, hands, etc.) even though he is not a physical being (Jn. 4:24; Lk. 24:39).
Anthropopathism, therefore, is a figure of speech by which human feelings or emotions are ascribed to God, in order to accommodate man’s ignorance of the unfathomable intentions and operations of deity (cf. Rom. 11:33-36). Professor Alan Cole has an excellent discussion of this figure as employed in the Exodus text under consideration.
“[Anthropopathism is a figure here used] by which God’s activity is explained, by analogy, in strictly human terms. The meaning is not that God changed His mind; still less that He regretted something that He had intended to do. It means, in biblical language, that He now embarked on a different course of action from that already suggested as a possibility, owing to some new factor which is usually mentioned in the context. In the Bible, it is clear that God’s promises and warnings are always conditional on man’s response: this is most clearly set out in Ezekiel 33:13-16. We are not to think of Moses as altering God’s purpose towards Israel by his prayer, but as carrying it out: Moses was never more like God than in such moments, for he shared God’s mind and loving purpose” (Exodus—Tyndale O.T. Commentaries, Downer’s Grove, IL: InterVarsity, 1973, p. 217; emphasis added).
It must be understood, therefore, that though certain biblical passages speak of the Lord being “changeless,” while others represent him as “changing” (in response to human conduct), that
different senses are in view. In light of this fact, the “discrepancy” problem dissolves. But when one does not understand some of the common figures of speech utilized by the Bible writers, under the guiding influence of the Holy Spirit, he most certainly will draw many faulty conclusions — sometimes very dangerous ones.