Dale Rose's link to Smith's Anthology Notes above doesn't work. This is the new clickey. Another version is in Lomax's The Folk Songs of North America (p. 480; with music & chords).

JOHN THE REVELATOR

1. [Dm]My Lord called John while he was a-writin',
My [Gm]Lord called John while [Dm]he was a-writin',
My Lord called John while he was a-writin'
[A7]'O John, John,
Seal up your [Dm]book, John,
An' don't you [A7]write no [Dm]more,
O [A7]John, John,
An' don't you write no [Dm]more.'

2. He wrote the Book of Revelations while he was a-writin', etc.

3. He wrote the book of Seven Seals while he was a-writin', etc.

~Masato