I have hated and abhorred deceit. In this verse he declares more distinctly what I have adverted to a little before, that he was cleansed from corrupt affections that he might bestow upon the law of God such honor and estimation as it deserved. Having elsewhere met with almost the same sentence, I shall but briefly touch upon the reason why the Prophet affirms that he hated deceit before he speaks of his love and devotedness to the law. As hypocrisy is in the hearts of all men by nature, and as we are naturally prone to vanity and deceitfulness, we ought diligently to labor to purge our hearts, that the love of the law may reign in them. Now if the beginning of a good life and the first point of righteousness is to hate and abhor deceit, it follows that nothing is more excellent than integrity; for unless that virtue hold the chief place, all the other virtues speedily disappear. Nor is abhorring superfluously added to hating, the design being to teach us that it is not enough to hate falsehood with a common hatred, but that God's children must hate it with a deadly hatred. Now if the love of the law and the hatred of falsehood are inseparably conjoined, it is a plain inference that all who are not taught in the school of God are infected with deceit and hypocrisy.

I hate and abhor lying - The mention of lying here particularly seems to have been suggested by the necessity, from the structure of the psalm, of finding some word at the beginning of the verse which commenced with the letter Schin. At the same time, it is an illustration of the nature of piety, and doubtless there had been numerous occasions in the life of the psalmist when he had seen and experienced the effects of falsehood. This sin, therefore, might occur to him as readily as any other. It is unnecessary to say that religion "forbids" this sin in all its forms.
But thy law do I love - Particularly here the law which forbids lying. The psalmist was conscious, as every good man must be, that he truly loved that pure law which forbids falsehood in all its forms.

I - abhor lying - Perhaps they might have made the confessions which the Chaldeans required, and by mental reservation have kept an inward firm adherence to their creed; but this, in the sight of the God of truth, must have been lying; and at such a sacrifice they would not purchase their enlargement, even from their captivity.

I hate and abhor lying,.... The sin of lying in common conversation, which owes its rise to Satan, the father of lies; is common to human nature, though very dishonourable to it; exceeding unbecoming a professor of religion; and was greatly hated by David, as it ought to be by all good men, Psalm 101:7. Or "falsehood" (k); false doctrine; everything contrary to the truth of the word of God, with all false worship, superstition, and idolatry; and this may the rather be thought to be designed, since the law or doctrine of God is opposed to it in the next clause;
but thy law do I love; because holy, just, and true; he being a regenerate man, and having it written on his heart, he loved both the precepts of the law and the doctrines of the Gospel: or, "thy doctrine"; the doctrine concerning God, his mind and will, his grace and love; see Psalm 119:97.
(k) "falsitatem", Montanus, Junius & Tremellius, Piscator, Cocceius, Gejerus, Michaelis.

lying--that is, as in Psalm 119:29, unfaithfulness to the covenant of God with His people; apostasy.