10 “Things burned with fire, and dug up, by the rebuke of Your countenance shall perish”. What are the things burned with fire and dug up which shall perish from the rebuke of His countenance? Let us see and perceive what are the things burned with fire and dug up. Christ has rebuked what? Sins: by the rebuke of His countenance sins have perished. Why then are sins burned with fire and dug up? Of all sins, two things are the cause in man, desire and fear. Think, examine, question your hearts, sift your consciences, see whether there can be sins, except they be either of desire, or of fear.
There is set before you a reward to induce you to sin, that is, a thing which delights you; you do it, because you desire it. But perchance you will not be allured by bribes; you are terrified with menaces, thou do it because you fear. A man would bribe you, for example, to bear false witness. Countless cases there are, but I am setting before you the plainer cases, whereby ye may imagine the rest. Have you hearkened unto God, and have you said in your heart, “What does it profit a man, if he gain the whole world, but of his own soul suffer loss?” I am not allured by a bribe to lose my soul to gain money.
He turns himself to stir up fear within you, he who was not able to corrupt you with a bribe, begins to threaten loss, banishment, massacres, perchance, and death. Therein now, if desire prevailed not, perchance fear will prevail to make you sin....What had evil fear done? It had dug up, as it were. For love does inflame, fear does humble: therefore, sins of evil love, with fire were lighted: sins of evil fear were dug up. On the one hand, evil fear does humble, and good love does light; but in different ways respectively.
For even the husbandman interceding for the tree, that it should not be cut down, says, “I will dig about it, and will apply a basket of dung.” The dug trench does signify the godly humility of one fearing, and the basket of dung the profitable squalid state of one repenting. But concerning the fire of good love the Lord says, “Fire I have come to send into the world.” With which fire may the fervent in spirit burn, and they too that are inflamed with the love of God and their neighbour. And thus, as all good works are wrought by good fear and good love, so by evil fear and evil love all sins are committed. Therefore, “Things set alight with fire and dug up,” to wit, all sins, “by the rebuke of Your countenance shall perish.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)