Why did the Israelites abandon the fight against the Moabites?

Can you explain 2 Kings 3:27? I know that there's only one God, and that he never loses, but this verse is a bit confusing. Why did Isreal experience great indignation, and where did it come from?

In 2 Kings 3, the kings of Israel, Judah and Edom unite to fight the Moabites. The Lord promotes the king of Judah through His prophet, Elisha, that these kings would see victory against the Moabites. The Lord sustains the armies in the desert by a supernatural provision of water to sustain the men and prove His willingness to bring victory. He also used the water to trick the Moabites into attacking.

In the battle, the armies of Israel, Judah and Edom successfully destroy the Moabite army:

2Kings 3:21 Now all the Moabites heard that the kings had come up to fight against them. And all who were able to put on armor and older were summoned and stood on the border.
2Kings 3:22 They rose early in the morning, and the sun shone on the water, and the Moabites saw the water opposite them as red as blood.
2Kings 3:23 Then they said, “This is blood; the kings have surely fought together, and they have slain one another. Now therefore, Moab, to the spoil!”
2Kings 3:24 But when they came to the camp of Israel, the Israelites arose and struck the Moabites, so that they fled before them; and they went forward into the land, slaughtering the Moabites.
2Kings 3:25 Thus they destroyed the cities; and each one threw a stone on every piece of good land and filled it. So they stopped all the springs of water and felled all the good trees, until in Kir-hareseth only they left its stones; however, the slingers went about it and struck it.
2Kings 3:26 When the king of Moab saw that the battle was too fierce for him, he took with him 700 men who drew swords, to break through to the king of Edom; but they could not.
2Kings 3:27 Then he took his oldest son who was to reign in his place, and offered him as a burnt offering on the wall. And there came great wrath against Israel, and they departed from him and returned to their own land.

As the Moabite king witnesses the end of his army, he makes an appeal to his pagan gods by sacrificing the most important thing he possessed: the heir to his throne. The text says the sacrifice took place on the wall that surrounded the Moabite king’s stronghold, which means it was done in full view of Israel’s troops.

The “great wrath” of v.27 that came against Israel was the wrath of the Moabite king, which was evidenced by his sacrifice of his own son. As a result of witnessing such a heinous act, Israel’s army decided they could not stand the wrath of the Moabite king. They had succeeded in putting down the Moabite rebellion and therefore decided it was not necessary to defeat the king in his city. Instead, they abandoned the fight and returned home.