And David laid up these words in his heart,.... Pondered upon them, and thought them over in his mind, finding that he was known, and his character also, and considered with himself what might be the consequence of this:

and was sore afraid of Achish the king of Gath; lest he should be set against him, and be prevailed upon by his servants to take away his life, or deliver him up into the hands of Saul.

But David took these words to heart, and was in great fear of Achish, lest he should treat him as an enemy, and kill him. In order to escape this danger, "he disguised his understanding (i.e., pretended to be out of his mind) in their eyes (i.e., before the courtiers of Achish), behaved insanely under their hands (when they tried to hold him as a madman), scribbled upon the door-wings, and let his spittle run down into his beard." The suffix to וישׁנּו is apparently superfluous, as the object, את־טעמו, follows immediately afterwards. But it may be accounted for from the circumstantiality of the conversation of every-day life, as in 2 Samuel 14:6, and (though these cases are not perfectly parallel) Exodus 2:6; Proverbs 5:22; Ezekiel 10:3 (cf. Gesenius' Gramm. 121, 6, Anm. 3). ויתו, from תּוה, to make signs, i.e., to scribble. The lxx and Vulgate render it ἐτυμπανίζειν, impingebat, he drummed, smote with his fists upon the wings of the door, which would make it appear as if they had read ויּתף (from תּפף), which seems more suitable to the condition of a madman whose saliva ran out of his mouth.

And David laid up these words in his heart, and was sore afraid of Achish the king of Gath.

21:12 Was afraid - Lest either their revenge or policy should prompt them to kill him. Perhaps he was the more apprehensive, because he wore Goliath's sword, which was probably well known at Gath. He now learned by experience what he afterward taught us, Psal 118:9. It is better to trust in the Lord, than to put any confidence in princes.

21:10-15 God's persecuted people have often found better usage from Philistines than from Israelites. David had reason to put confidence in Achish, yet he began to be afraid. His conduct was degrading, and discovered wavering in his faith and courage. The more simply we depend on God, and obey him, the more comfortably and surely we shall walk through this troublesome world.