But her end is bitter as wormwood, sharp as a two-edged sword.

Wesley's Notes

5:4 But - The effect of that to which she entices men, is destruction.

Jamieson-Fausset-Brown Bible Commentary

4. her end-literally, "her future," in sense of reward, what follows (compare Ps 37:37; 73:17). Its nature is evinced by the use of figures, opposite those of Pr 5:3. The physical and moral suffering of the deluded profligate are notoriously terrible.

Matthew Henry's Concise Commentary

5:1-14 Solomon cautions all young men, as his children, to abstain from fleshly lusts. Some, by the adulterous woman, here understand idolatry, false doctrine, which tends to lead astray men's minds and manners; but the direct view is to warn against seventh-commandment sins. Often these have been, and still are, Satan's method of drawing men from the worship of God into false religion. Consider how fatal the consequences; how bitter the fruit! Take it any way, it wounds. It leads to the torments of hell. The direct tendency of this sin is to the destruction of body and soul. We must carefully avoid every thing which may be a step towards it. Those who would be kept from harm, must keep out of harm's way. If we thrust ourselves into temptation we mock God when we pray, Lead us not into temptation. How many mischiefs attend this sin! It blasts the reputation; it wastes time; it ruins the estate; it is destructive to health; it will fill the mind with horror. Though thou art merry now, yet sooner or later it will bring sorrow. The convinced sinner reproaches himself, and makes no excuse for his folly. By the frequent acts of sin, the habits of it become rooted and confirmed. By a miracle of mercy true repentance may prevent the dreadful consequences of such sins; but this is not often; far more die as they have lived. What can express the case of the self-ruined sinner in the eternal world, enduring the remorse of his conscience!