As used by Paul, "works of the law" are works of obedience to the law given to Moses.
Yes, and there's also a New Testament tenor as "works of the law" being somebody who is obedient to the law, because it's on a list of religious requirements, not because they, in their heart, do so with any strong moral conviction and righteous intent, even rather than they're earning brownie points with God, that He's impressed, or to impress other people, that they're God's give to the human race.
The Pharisees were great keepers of the law, to "strain at a gnat" meaning they would shudder to swallow a tiny bug that eats blood, for the prohibition against eating blood, while, at the same time, harboring things like murderous hatred of the Lord Jesus, their very God! So, the phrase brings me to mind God's grace and faith required of Christianity, worshiping in Spirit and truth, in love, that it's nowhere and cursed to think the Lord wants our "works of the law," absent faith. It's a dark phrase to my mind I associate with evil Pharisees, or apostate and poisonous Judaizing "Christian" cults, because of Romans 3:27, Romans 9:32, Galatians 2:16, Galatians 3:2,5,10.
Of course, this has nothing to do with discounting obeying the Holy Spirit and answering the moral law also written on our hearts by the Holy Spirit in good conscience, again just pointing out that phrase is not generally accompanied by having anything good to saw about what the law can actually accomplish in lawless, unregenerate man, except convict us of sin and send us to hell.
Isaiah 64:6 But we are all as an unclean thing, and all our righteousnesses are as filthy rags; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away.
Romans 8:6-9 For to be carnally minded is death; but to be spiritually minded is life and peace. Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be. So then they that are in the flesh cannot please God. But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.
Here's to the drunk with legal fanaticism, just a slice of Matthew 23,
Matthew 23:23-27 Woe unto you, scribes and Pharisees, hypocrites! for ye pay tithe of mint and anise and cummin, and have omitted the weightier matters of the law, judgment, mercy, and faith: these ought ye to have done, and not to leave the other undone. Ye blind guides, which strain at a gnat, and swallow a camel [always thought this so funny a simile, that the Lord Jesus must have had a sense of humor]. Woe unto you, scribes and Pharisees, hypocrites! for ye make clean the outside of the cup and of the platter, but within they are full of extortion and excess. Thou blind Pharisee, cleanse first that which is within the cup and platter, that the outside of them may be clean also. Woe unto you, scribes and Pharisees, hypocrites! for ye are like unto whited sepulchres, which indeed appear beautiful outward, but are within full of dead men's bones, and of all uncleanness.
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