He changed his behaviour. — These very words (with the substitution of Abimelech for Achish, a name which, as has been above suggested, seems to have been the “nomen dignitatis” for generations of Philistine kings) are found in the title of Psalms 34. The poem in question is, however, of a general, not of an historical character, and especially celebrates Jehovah’s guardian care of the righteous. Its “acrostic” arrangement, however, suggests a later date than the time of David. If, as is quite possible, the royal psalmist was the original author, and that the deliverance on the present occasion suggested the theme, then it must have been brought into its present form by some later temple musician.
Feigned himself mad. — Literally, he roamed hither and thither, restless and in terror. — Dean Payne Smith. “In their hands,” that is, “in their presence.” Some have supposed that the madness was not “simulated,” but real. Wrought upon by excitement of fear and terrible anxiety, it has been suggested that the mind for a time lost its balance, and that David became temporarily really insane; but the sense of the narrative plainly indicates that the madness was feigned.
Scrabbled on the doors of the gate. — Scratched on them; “scrabble” being probably a diminutive of “scrape” (Richardson, Dictionary). By others it is connected with “scribble.” the root in either case being ultimately the same. The LXX. and Vulg. apparently translate from a slightly different word, and instead of “scrabbled,” render “drummed” (impingebat) on the wings of the doors.
Let his spittle fall. — That is, allowed the foam which comes from the mouth of a madman to hang about his beard. It has been cleverly suggested that David was only too well acquainted with all the signs of madness, from his long and intimate association with King Saul in his darker hours of insanity. There are other well-authenticated examples in history of great heroes, in seasons of sore danger, feigning madness like David, with a view of escaping from their enemies. For instance, according to the Shâhnâmeh, Kai Khosrev feigned idiocy in face of mortal peril.