In Hebrew, the word לָדוּם “stand still” literally means “be silent.” In this context, Joshua was commanding the sun “to be silent,” and I guess that means to stop shining. Since the sun was rising in the east, his demand to the sun was that it keeps from shining.
When Joshua came to have a fight with the Amorites, he came at night and surprised them. Joshua was helped by the darkness, caused by a huge storm that formed hailstones so big that it killed a lot of people. The Bible says that more people died from the hailstones than those of Israel killed with the sword!
Since the hailstorm didn't affect Israel's army, Joshua really needed the storm to last longer so that the hail could keep on wiping out the army of the Amorites. Consequently,