Warren Steel, who is at the Department of Music at the University of Mississippi, had access to the original poem, by Edward Young. His “Night Thoughts” was a popular series of poems–Blake illustrated them, for example. Steel wrote on the Sacred Harp mailing list:
I have a copy of Young’s Night Thoughts handy. Night 4 is the Christian Triumph.
–in his bless’d life,
I see the path, and in his death, the price,
And in his great ascent, the proof supreme
Of immortality. –And did he rise?
Hear, O ye nations! hear it, O ye dead!
He rose! he rose! he burst the bars of death…
The theme, the joy, how then shall man sustain!
Oh the burst gates! crush’d sting! demolish’d throne!
Last gasp of vanquish’d death! Shout earth and heav’n
This sum of joy to man: whose nature then
Took wing, and mounted with him from the tomb!
Then, then I rose; then first humanity
Triumphant pass’d the crystal ports of light
(Stupendous guest!) and seiz’d eternal youth,
Seiz’d in our name. E’er since, ’tis blasphemous
To call man mortal. Man’s mortality
Was then transferr’d to death; and heav’n’s duration
Unalienably seal’d to this frail frame,
This child of dust–Man, all-immortal! hail!
Hail heaven! all-lavish of strange gifts to man!
Thine all the glory, man’s the boundless bliss.
So, since the resurrection, the poet views man
immortal; it’s he being hailed first. Then heaven,
or God is hailed as generous of gifts that are
strange (i.e. immortality). The glory belongs to
heaven, the bliss belongs to man. So I read it.
I think he’s right. I’m also convinced now that “all-lavish of [strange gifts]” is a adjectival phrase, like “God almighty” or “God all-powerful“. Note the parallelism in the poem to “all-immortal”.