The biblical allusion in Henry Wadsworth Longfellow's poem "A Psalm of Life" is to Genesis 3:19. This is spoken by God to Adam when he and Eve are being evicted from the Garden of Eden for disobeying God's command not to taste of the fruit of the Tree of Knowledge of Good and Evil.
In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art, and unto dust shalt thou return.
In "A Psalm of Life," the poet says in the second stanza:
Life is real! Life is earnest!
And the grave is not its goal;
Dust thou art, to dust returnest,
Was not spoken of the soul.
The poem was first published in 1838 in The Knickerbocker Magazine
. At that time, most Americans were churchgoers and believed literally in the words of both the Old and New Testaments. Longfellow was one of them. This explains his great popularity as a poet during the nineteenth century, as well as the fact that his reputation has declined ever since. The "Summary" section of the eNotes study guide for "A Psalm of Life" (see reference link below) states the poem is often mocked by critics today because of its incoherent imagery
and empty rhetoric
. One example of allegedly empty rhetoric is the idea that we can leave "footprints on the sands of time" through diligent effort. Footprints will not last long enough on sands to do our successors any good.