1 Samuel 21

7. Doeg, an Edomite--who had embraced the Hebrew religion.
detained before the Lord--at the tabernacle, perhaps, in the performance of a vow, or from its being the Sabbath, which rendered it unlawful for him to prosecute his journey.
the chiefest of the herdmen that belonged to Saul--Eastern monarchs anciently had large possessions in flocks and herds; and the office of the chief shepherd was an important one.

1 Samuel 21:9 . HE TAKES GOLIATH'S SWORD.

1 Samuel 21:10-15 . AT GATH HE FEIGNS HIMSELF MAD.

10. David . . . fled . . . to Achish the king of Gath--which was one of the five principalities of the Philistines. In this place his person must have been known, and to venture into that country, he their greatest enemy, and with the sword of Goliath in his hand, would seem to have been a perilous experiment; but, doubtless, the protection he received implies that he had been directed by the divine oracle. Achish was generous ( 1 Samuel 27:6 ). He might wish to weaken the resources of Saul, and it was common in ancient times for great men to be harbored by neighboring princes.

13. feigned himself mad--It is supposed to have been an attack of epilepsy, real or perhaps only pretended. This disease is relieved by foaming at the mouth.
let his spittle fall down upon his beard--No wonder that Achish supposed him insane, as such an indignity, whether done by another, or one's self, to the beard, is considered in the East an intolerable insult.