Charles H. Spurgeon on Psalms 119:29

Remove from me the way of lying. This is the way of sin, error, idolatry, folly, self righteousness, formalism, hypocrisy. David would not only be kept from that way, but have it kept from him; he cannot endure to have it near him, he would have it swept away from his sight. He desired to be right and upright, true and in the truth; but he feared that a measure of falsehood would cling to him unless the Lord took it away, and therefore he earnestly cried for its removal. False motives may at times sway us, and we may fall into mistaken notions of our own spiritual condition before God, which erroneous conceits may be kept up by a natural prejudice in our own layout, and so we may be confirmed in a delusion, and abide under error unless grace comes to the rescue. No true heart can rest in a false view of itself; it finds no anchorage, but is tossed to and fro till it gets into the truth and the truth into it. The true born child of heaven sighs out and cries against a lie, desiring to have it taken away as much as a man desires to be set at a distance from a venomous serpent or a raging lion.

And grant me thy law graciously. He is in a gracious state who looks upon the law itself as a gift of grace. David wishes to have the law opened up to his understanding, engraved upon his heart, and carried out in his life; for this he seeks the Lord, and pleads for it as a gracious grant. No doubt he viewed this as the only mode of deliverance from the power of falsehood: if the law be not in our hearts the lie will enter. David would seem to have remembered those times when, according to the eastern fashion, he had practised deceit for his own preservation, and he saw that he had been weak and erring on that point; therefore he was bowed down in spirit and begged to be quickened and delivered from transgressing in that manner any more. Holy men cannot review their sins without tears, nor weep over them without entreating to be saved from further offending.

There is an evident opposition between falsehood and the gracious power of God's law. The only way to expel the lie is to accept the truth. Grace also has a clear affinity to truth: no sooner do we meet with the sound of the word "graciously" than we hear the footfall of truth: "I have chosen the way of truth." Grace and truth are ever linked together, and a belief of the doctrines of grace is a grand preservative from deadly error.

In the fifth of the preceding octave (Psalms 119:21) David cries out against pride, and here against lying these are much the same thing. Is not pride the greatest of all lies?