Peter Pett's Commentary on the Bible
Psalms 64:7-9
But God Has Taken Note And Will Turn Their Schemes Back On Their Own Heads So That All Will See Their Folly And Recognise In Their Demise The Hand Of God (Psalms 64:7).
His adversaries thought that no one noted what they were doing (Psalms 64:5), but they will soon find out that they were wrong. For God in turn will shoot His arrows at them, and ‘suddenly' they will be wounded. He will return what they have been whispering on their own heads through the triumph of David. Thus their own tongue will be against them, for it will have brought them into disrepute. In view of David's continual triumphs over apparent disaster his adversaries continually found their harsh words returning on their heads, and regretted that they had spoken them.
And all who see the retribution that David's adversaries have brought on themselves, will shake their head at their folly. And they themselves will fear, and declare the work of God, taking notice of what He does. So the folly of David's adversaries will be a lesson to the world.
‘But God will shoot at them,
With an arrow will they suddenly be wounded,
So they will they make them stumble,
Their own tongue being against them,
All who see them will wag the head,
And all men will fear,
And they will declare the work of God,
And will wisely consider of his doing.'
‘God will shoot at them, with an arrow will they suddenly be wounded' or possibly, ‘God will shoot at them with an arrow, suddenly will they be wounded'. Either way the stress is on the fact that they who have aimed their arrows (‘even bitter words') at David ‘suddenly and without fear' behind his back (Psalms 64:5), will themselves find that David's God will shoot His arrows at them equally suddenly. His powerful word will go forward to do His will (compare Isaiah 55:10). God's mysterious instruments of justice, ‘they' (compare Psalms 63:10), will make them stumble. With unexpected suddenness they will find themselves wounded. Their own tongues, with which they had been surreptitiously attacking David, will react against them. They had acted without fear. But if they had known David's God, and the forces at His disposal, they would have been afraid indeed.
Indeed all who see what happens to them will ‘wag their heads' with amazement at their folly, and they will be afraid, for they will have seen what God can do. And they will declare what God has done, and wisely think about and consider it. Thus will David's tribulations bring glory to God.