John Calvin Commentary Psalms 78:33

"Therefore their days did he consume in vanity, And their years in terror." — Psalms 78:33 (ASV)

And he consumed their days in vanity. The Psalmist here speaks of the whole people, as if he had said that all without exception, from the least to the greatest, were quickly consumed.

This could likely refer to that most severe punishment, confirmed and ratified by God’s wrath—that they would all perish in the wilderness with only two exceptions, Joshua and Caleb, because they had turned back when already near the land of Canaan.

That vast multitude, therefore, after they had barred their own entry into the Holy Land, died in the wilderness during the course of forty years. Days are mentioned first, and then years; this intimates that the duration of their life was cut short by God’s curse, and that it was quite apparent they perished in the midst of their course. Their days, then, were consumed in vanity; for they vanished away like smoke: and their years in haste, because they passed swiftly away like a stream.

The word בהלה, behalah, translated here as haste, is rendered by some as terror. I would prefer to interpret it as tumult, for it undoubtedly means that their life was taken away, much like when something is forcibly seized in a tumult. However, I am not inclined to change the word haste, which brings out the meaning more clearly.

It was a display of righteous retribution for their obstinacy that their strength, which had made them proud, thus withered and suddenly vanished like a shadow.