121 and the Lord sent Nathan to David. He came to him, and said to him, "There were two men in a certain city, the one rich and the other poor. 2 The rich man had very many flocks and herds; 3 but the poor man had nothing but one little ewe lamb, which he had bought. He brought it up, and it grew up with him and with his children; it used to eat of his meager fare, and drink from his cup, and lie in his bosom, and it was like a daughter to him. 4 Now there came a traveler to the rich man, and he was loath to take one of his own flock or herd to prepare for the wayfarer who had come to him, but he took the poor man's lamb, and prepared that for the guest who had come to him." 5 Then David's anger was greatly kindled against the man. He said to Nathan, "As the Lord lives, the man who has done this deserves to die; 6 he shall restore the lamb fourfold, because he did this thing, and because he had no pity."
Matthew Henry's Commentary on 2 Samuel 12:1-6
Commentary on 2 Samuel 12:1-14
(Read 2 Samuel 12:1-14)
God will not suffer his people to lie still in sin. By this parable Nathan drew from David a sentence against himself. Great need there is of prudence in giving reproofs. In his application, he was faithful. He says in plain terms, Thou art the man. God shows how much he hates sin, even in his own people; and wherever he finds it, he will not let it go unpunished. David says not a word to excuse himself or make light of his sin, but freely owns it. When David said, I have sinned, and Nathan perceived that he was a true penitent, he assured him his sin was forgiven. Thou shalt not die: that is, not die eternally, nor be for ever put away from God, as thou wouldest have been, if thou hadst not put away the sin. Though thou shalt all thy days be chastened of the Lord, yet thou shalt not be condemned with the world. There is this great evil in the sins of those who profess religion and relation to God, that they furnish the enemies of God and religion with matter for reproach and blasphemy. And it appears from David's case, that even where pardon is obtained, the Lord will visit the transgression of his people with the rod, and their iniquity with stripes. For one momentary gratification of a vile lust, David had to endure many days and years of extreme distress.