What is the significance of 1 Chronicles 21:15?

“And God sent an angel to Jerusalem to destroy it; but when he was about to destroy it, the Lord took note and relented concerning the calamity; he said to the destroying angel, ‘Enough! Stay your hand.’”

This powerful passage tells us why God sent the angel and why he changed his mind. If God foreknew he was not going to destroy Jerusalem, he could not have genuinely intended to destroy it and the Scripture which explicitly tells us “he was about to destroy it” must be considered incorrect. Moreover, if God never really intended to destroy the city, his dispatching the angel for the expressed purpose of doing so becomes altogether unintelligible. Nor could he have authentically “relented” from a previous plan, for he never really planned this destruction in the first place.

The classical view of an exhaustively settled future introduces a certain artificiality into texts such as this one which depict God as changing his plans. For this reason, I believe we should reject this view of the future and accept that God can truly change his mind about temporal matters.