The closest line in a spiritual I've been able to find is probably unrelated, or at most an echo of "This mornin', this evenin', so soon:

Had to get up this mornin', soon, soon,
Had to get up this mornin', soon.

But Odum and Johnson, in Negro Workaday Songs, 163, do have an interesting lesbian-related song from the woman's viewpoint whose last line makes it a possible distant relation:

DERE'S A LEZZIE AFTER MY MAN

Dere's a lezzie after my man,
Dere's a lezzie after my man,
She'll get him if she can,
'Cause I kotch her holdin' his hand,
Dis a-mawnin', dis evenin, more'n late.

Her face am powdered white (2)
Her hair am greasy and slick,
On my man she try to work her trick,
Dis a-mawnin', dis evenin' more'n soon.

She comed round to my do' (2)
Den I ripped offen her skirt,
Den I tore offen his shirt,
Dis a-mawnin', dis evenin' more'n soon.

Trouble is, Odum and Johnson don't give sources! Frustrating.

Bob