Jamieson, Fausset and Brown on 1 Samuel 19:8-10

8-10. David went out, and fought with the Philistines, and slew them with a great slaughter--A brilliant victory was gained over the public enemy. But these fresh laurels of David reawakened in the moody breast of Saul the former spirit of envy and melancholy. On David's return to court, the temper of Saul became more fiendish than ever; the melodious strains of the harp had lost all their power to charm; and in a paroxysm of uncontrollable frenzy he aimed a javelin at the person of David--the missile having been thrown with such force that it pierced the chamber wall. David providentially escaped; but the king, having now thrown off the mask and being bent on aggressive measures, made his son-in-law's situation everywhere perilous.