What does Joshua 10:15 mean?

Then Joshua spoke to Yahweh in the day when Yahweh delivered up the Amorites before the children of Israel. He said in the sight of Israel, “Sun, stand still on Gibeon! You, moon, stop in the valley of Aijalon!”

The sun stood still, and the moon stayed, until the nation had avenged themselves of their enemies. Isn’t this written in the book of Jashar? The sun stayed in the middle of the sky, and didn’t hurry to go down about a whole day.

There was no day like that before it or after it, that Yahweh listened to the voice of a man; for Yahweh fought for Israel.

These five kings fled, and hid themselves in the cave at Makkedah.

Joshua was told, saying, “The five kings have been found, hidden in the cave at Makkedah.”

Joshua said, “Roll large stones to cover the cave’s entrance, and set men by it to guard them;