Shortly before he died, Johnny Cash scrawled down eight short lines in a shaky hand, mortality clearly on his mind.

“You tell me that I must perish/Like the flowers that I cherish,” he wrote. He considered the hell of “nothing remaining of my name,” before concluding with an affirmation of his own legacy:

But the trees that I planted

Still are young

The songs I sang

Will still be sung

That poem, “Forever,” is part of a new collection, “Forever Words: The Unknown Poems” (Blue Rider Press), to be published next week. Edited by Paul Muldoon, a Pulitzer Prize-winning poet and Princeton professor, the book includes 41 works from throughout Cash’s life — the earliest piece, “The Things We’re Frightened At,” was done when he was 12 — that were among the papers left behind when Cash died in September 2003.

In some ways the poems mirror Cash’s songwriting, with terse ballads of outsiders in love, and parables drawn from the Bible; Cash’s version of Job is a wealthy cattleman who “cried out in agony/When he lost his children and his property.” And for Cash, who in his last years drew a new audience with a set of stark and fragile recordings, the poems present yet another look at a legend of American music.