Notice that the psalmist said that he did it; he turned his feet into the way of conformity to God’s Word. He didn’t say that he thought on his ways and then prayed, ‘Oh Lord, turn my feet.’ He said, ‘I turned my feet.’ In other places in Psalm 119, he prayed that God would turn him. And in our text he has told us that he entreated God’s favor with his whole heart. He was a praying man. He lived in the climate of dependence on God’s power; but he didn’t expect the grace of God to bypass the conscious action of his own will.
[Martin, Albert N., A Life of Principled Obedience (Banner of Truth Trust, 1992), pg. 15]