Charles H. Spurgeon on Psalms 119:150

They draw nigh that follow after mischief. He could hear their footfalls close behind him. They are not following him for his benefit, but for his hurt, and therefore the sound of their approach is to be dreaded. They are not prosecuting a good object, but persecuting a good man. As if they had not enough mischief in their own hearts, they are hunting after more. He sees them going a steeple chase over hedge and ditch in order to bring mischief to himself, and he points them out to God, and entreats the Lord to fix his eyes upon them, and deal with them to their confusion. They were already upon him, and he was almost in their grip, and therefore he cries the more earnestly.

They are far from thy law. A mischievous life cannot be an obedient one. Before these men could become persecutors of David they were obliged to get away from the restraints of God's law. They could not hate a saint and yet love the law. Those who keep God's law neither do harm to themselves nor to others. Sin is the greatest mischief in the world. David mentions this to the Lord in prayer, feeling some kind of comfort in the fact that those who hated him hated God also, and found it needful to get away from God before they could be free to act their cruel part towards himself. When we know that our enemies are God's enemies, and ours because they are his, we may well take comfort to ourselves.