John Gill Bible Commentary

Which imagine mischiefs in their heart,.... This shows that not a single person barely is meant but more, as Saul's courtiers; who were secretly and continually meditating mischief against David, traducing him to Saul, and devising things to take away his life. Such were the Jews to Christ, who were always plotting to entangle him, or contriving to kill him; and so wicked men are ever devising mischief against the quiet in the land, which is very abominable to God; and rightly observed here, to prevail upon the Lord to preserve from them, Psa 2:1; continually are they gathered together for war; so Saul gathered together three thousand men, and went in pursuit of David, as an enemy, to take him. So Herod and Pontius Pilate joined together, though before enemies, in the prosecution of Christ; and Jews and Gentiles gathered together against him: so the saints, being in a warfare state, have their enemies, who often combine against them, and attack them, and will not suffer them to be at rest and peace; as sin, Satan, the world, and false teachers; see Psa 120:7.