Adam Clarke on Psalms 90:5

Thou carriest them away as with a flood - Life is compared to a stream, ever gliding away; but sometimes it is as a mighty torrent, when by reason of plague, famine, or war, thousands are swept away daily. In particular cases it is a rapid stream, when the young are suddenly carried off by consumptions, fevers, etc.; this is the flower that flourisheth in the morning, and in the evening is cut down and withered. The whole of life is like a sleep or as a dream. The eternal world is real; all here is either shadowy or representative. On the whole, life is represented as a stream; youth, as morning; decline of life, or old age, as evening, death, as sleep; and the resurrection as the return of the flowers in spring. All these images appear in these curious and striking verses, Psa 90:3-6.