Even though the Philistines initially appeared to be discouraged by the arrival of the ark, it actually served to rally them as they called on one another to be strong and fight. Previously, in Deuteronomy 11:25, the Lord promised that he would put great fear upon the enemies of Israel so that they will flee before them (see Exodus 23:27).1 Seeing as Israel was under his wrath, however, their enemies rallied against them instead of panicking in fear.
9 Fortifiez-vous et soyez des hommes, Philistins, de peur que vous ne soyez asservis aux Hébreux comme ils vous ont été asservis; soyez des hommes et combattez!