When the Philistines heard the noise of the shout, they said, What means the noise of this great shout in the camp of the Hebrews? They understood that the ark of Yahweh was come into the camp.
and they understood that the ark of the Lord was come into the camp: this they understood by spies, which they sent to find out the meaning of the shout; which is more probable than that they came to the knowledge of it by deserters; seeing it is not very likely that any Israelites would desert to the Philistines.