Psalms 99:8 - Joseph Benson’s Commentary on the Old and New Testaments

Thou answeredst them, O Lord Namely, the intercessors before mentioned. Thou forgavest them Either, 1st, Moses and Aaron, who sinned, and whose sins God pardoned, yet so that he punished them with exclusion from the land of Canaan. Or rather, 2d, The people, for whom they prayed; for this forgiving was evidently the effect of God's answering the prayers of the persons above mentioned; and, therefore, as their prayers, recorded in Scripture, were not for the pardon of their own, but for the pardon of the people's sins, so this forgiveness granted was for the sins of the people. Though thou tookest vengeance of their inventions This clause limits and explains the former. Thou didst forgive the sins of the people, not absolutely and universally, for thou didst punish them severely, but so far as not to inflict that total and final destruction upon them which they deserved, and thou hadst threatened: see Exodus 32:10; Exodus 32:14; Exodus 32:34.