John Gill's Exposition of the Whole Bible
Proverbs 20:17
Bread of deceit [is] sweet to a man,.... Which may be understood of sin in general, which is bread to the sinner, he eats it: it is called "the bread of wickedness", Proverbs 4:17; but it is but poor bread, no other than ashes Isaiah 44:20; it is "bread of deceit"; there is a deceitfulness in all sin; it is in appearance fair and pleasant to the eye, like the fruit our first parents ate of; or like the apples of Sodom, of which it is reported that they are very beautiful to look at, but when touched drop into ashes; sin promises pleasure, profit, honour, liberty, peace, and impunity, yet gives neither; but the reverse, pain, loss, shame, servitude distress, and destruction; and yet it is sweet to an unregenerate man, one of a vicious taste, or whose taste remains unchanged; it is natural to him and he takes as much delight in it as in eating and drinking; and especially such sins as are called constitution ones, which he is not easily prevailed upon to part with; wickedness is sweet in his mouth, he rolls it and keeps it as a sweet morsel under his tongue, and forsakes it not,
Job 20:12. It may be applied to particular sins, as to adultery, as it is by Jarchi, and with which may be compared Proverbs 9:17; and to riches unlawfully gotten; see Job 20:15; and to the cruel usage and persecution of the people of God, called the bread of wickedness and wine of violence, which wicked men take as much delight in as in eating and drinking, Proverbs 4:17; particularly the cruelty of the church of Rome, who has made herself drunk with the blood of the saints, in which she delights, and will be bitter to her in the end,
Revelation 17:6. It may be interpreted of false doctrine; so the doctrine of the Pharisees and Sadducees is signified by leavened bread,
Matthew 16:6; this is not true bread, does not strengthen, nourish, and refresh, as the Gospel does, but eats as a canker; it is not solid and substantial, but mere chaff, it is bread of falsehood and lying; false teachers lie in wait to deceive, their doctrines are lies in hypocrisy, and, yet these are sweet unto, and taken down greedily by carnal persons; particularly the doctrine of justification by works: this is the bread some men live on, but it is only husks which swine eat; it is feeding on wind, and filling the belly with east wind, which swells and vainly puffs up the fleshly mind; it is contrary to the, Gospel, and is not of the truth, and will deceive persons that trust to it; and yet it is sweet to a natural man; his own righteousness, and to trust to it, is natural to him; it is his own, and what he has laboured for, and is fond of; it affords room for boasting, and he does not care to part with it;
but afterwards his mouth shall be filled with gravel; with that which will be ungrateful, uncomfortable, and distressing to him; the conscience of a sinner, who has been taking his fill of sin and pleasure in it shall be filled with remorse and distress; and with bitter reflections upon himself; with a dreadful sense of divine wrath, and fearful apprehensions of it now; and destruction and damnation will be his portion hereafter; and this will be the consequence of all false doctrine, and of a man's trusting to his own righteousness and despising Christ's; see 2 Peter 2:1.