en_obs-tn/content/15/08.md

to reach the Gibeonites

This could mean to get to the Gibeonites or to arrive at where the Gibeonites lived. The Gibeonites lived in Canaan, but Canaan is big enough that it took all night for the Israelite army to travel from their camp to where the Gibeonites were.

they surprised the Amorite armies

The Amorites did not know that the Israelites were coming to attack them.