David asked God to keep him from the wicked in the world who are vicious and proud.
17:6-7 The psalmist based his request on God's loyal love for him as seen in His deliverance of those who take refuge in Him. He called on God to deliver him immediately.
17:8 The apple of the eye evidently refers to the pupil, the source of sight. With this figure David was asking God to keep him in the center of his vision, not to let him out of His sight but to keep His eye on him. David also expressed his need for God's careful protection through the image of a bird protecting its young under its wings (cf. Deut. 32:10-11; Ruth 2:12; Matt. 23:37).
17:9-12 Whatever the situation in David's life was to which he referred in this psalm it is clear from these verses that David's enemies were surrounding him (figuratively if not literally, cf. 22:12-18). They determined to kill him. They appear to have been confident of their success too. Their eyes were on David even as were the Lord's (v. 8a), but there was hatred in their gaze. Rather than protecting him lovingly as a mother bird (v. 8b) they were out to tear him apart and devour him as a lion does its prey, by sneaking around and attacking.
