Let him accept an offering - If God have stirred thee up against me, why, then, let him deliver my life into thy hand, and accept it as a sacrifice. But as the word is מנחה minchah, a gratitude-offering, perhaps the sense may be this: Let God accept a gratitude-offering from thee, for having purged the land of a worker of iniquity; for, were I not such, God would never stir thee up against me.
But if they be the children of men - If men have, by false representations, lies, and slanders, stirred thee up against an innocent man, then let them be cursed before the Lord. If I am guilty, I deserve to die; if not, those who seek my life should be destroyed.
Saying, Go, serve other gods - His being obliged to leave the tabernacle, and the place where the true worship of God was performed, and take refuge among idolaters, said in effect, Go, serve other gods.
If the Lord have stirred thee up - The meaning is clear from the preceding history. “An evil spirit from God troubling him” was the beginning of the persecution. And this evil spirit was sent in punishment of Saul‘s sin 1 Samuel 16:1, 1 Samuel 16:14. If the continued persecution was merely the consequence of this evil spirit continuing to vex Saul, David advises Saul to seek God‘s pardon, and, as a consequence, the removal of the evil spirit, by offering a sacrifice. But if the persecution was the consequence of the false accusations of slanderers, then “cursed” be his enemies who, by their actions, drove David out from the only land where Yahweh was worshipped, and forced him to take refuge in the country of pagan and idolaters (compare Deuteronomy 4:27; Deuteronomy 28:36).