So David did as the LORD had commanded him, and he struck down the Philistines all the way from Gibeon to Gezer.

Joshua 12:12
the king of Eglon, one; the king of Gezer, one;

Joshua 21:21
they were given Shechem in the hill country of Ephraim (a city of refuge for the manslayer), Gezer,

Isaiah 28:21
For the LORD will rise up as at Mount Perazim. He will rouse Himself as in the Valley of Gibeon, to do His work, His strange work, and to perform His task, His disturbing task.

And David did so, as the LORD had commanded him; and smote the Philistines from Geba until you come to Gazer.