King Mesha of Moab fought against the kings of Yisrael, Yehuda and Edom (2 Melachim chapter 3). The navi Elisha prophecies, under oath, that the Jews will be successful. However at the end of the chapter Mesha sacrifices his son (or perhaps the son of the king of Edom) which somehow causes a reversal of fortune with Mesha and Moav remaining undefeated.
This story is puzzling. What has Mesha achieved in killing his son? He was not commanded to do so by God, in fact it violates one of the 7 noachide laws. This is equally true if he killed the son of the Edomite king. Why then would God turn things in his favor as a result of this act? Furthermore the navi already said there would be victory. We have a principle that a positive prophecy will not be revoked.
How do we understand these turn of events?