Charles H. Spurgeon on Psalms 99:8

Thou tookest vengeance. Sometimes the sins of a people may be such, that God will not pardon them as to temporal punishments; nay, not the godly themselves. Even they may have been partakers with others in their sins, or may have so provoked God themselves, and sinned in such a way as to cause his name to be blasphemed; so that he is concerned in honour to bring some exemplary punishment upon them. So it was with David (2Sa 12:10-14.): though he pardoned him as to the guilt of eternal death, saved his soul, and spared his life, which was forfeited to divine justice for the murder of Uriah; yet the prophet announced that sharp afflictions must come on him, the sword must never "depart front his house, "and the child begotten in adultery must die, and his wives must be given to his neighbours. So, in Ps 99:8, it seems to be spoken of Moses himself, and other godly among the Israelites who died in the wilderness, and were not permitted to come into the land of promise, that "God forgave them, "yet "took vengeance of their inventions, " John Collins (1687) in the Morning Exercises.