Behold, God is mine helper: the Lord is with them that uphold my soul. Behold, God is mine helper - This would naturally occur to him when he saw that Saul was obliged to leave the pursuit, and go to defend his territories, when he was on the very point of seizing him. God, whose providence is ever watchful, had foreseen this danger and stirred up the Philistines to make this inroad just at the time in which Saul and his army were about to lay hands on David. Well might he then say, "Behold, God is mine helper."
Is with them, that uphold my soul - נפשי naphshi, my life. This may even refer to the Philistines, who had at this time made an inroad on Israel. God was even with his own enemies, by making them instruments to save the life of his servant.