"Lawd, Ah wuz" in the Parrish version is something like a prefixed interpolation to "down on my knees." I've found still another seemingly related colorful version (no "one morning soon" lines, though).

I HEARD THE ANGELS SINGIN'

Who is that yonder all dressed in red?
I heard the angels singin';
It look like the children Moses led,
I heard the angels singin'.

Down on my knees,
Down on my knees,
I heard the angels singin'.

Well, who that yonder all dressed in black?
I heard the angels singin';
It looks like it's de mourners jus' got back,
I heard the angels singin'.

Yes, who's that yonder all dressed in blue?
It looks like the children just come through.

From: Odum & Johnson, The Hegro and His Songs (1925; Negro Universities Press, 1968, p. 140; text only)

~Masato