Betting that the Philistines hated Saul even more than they hated him, David sought safety among his erstwhile enemies. However, when the lyric that had caused him so much trouble with King Saul’s jealousy caught up with him in Gath (“David has killed his multitudes”), David became afraid. David feigned madness by some sort of loud display, scratching on doors, and drooling. The ruse worked, and David escaped.
This passage is important for at least a couple of reasons. First, this is an indigenous understanding of how mental health problems present themselves that must be read as a counter-example to the evil spirit from the LORD being sent on Saul.
Second, this is the first of a couple of times that David will venture to Goliath’s hometown. His reception is not altogether negative. Eventually David will raise up Philistine soldiers, including David’s close friend and trusted commander, Ittai from Gath (2 The judge who anointed the first two kings of Israel More 18:2). Surprisingly, David will continue to find support from at least one of the Philistine cities.