From the outset, this highly intricate spiritual operates on multiple poetic levels.
Shouting Oh Mary don't you weep! we're immediately placed with St John at the foot of the Cross on Good Friday, comforting the Mother of God, before the lyric suddenly expands unexpectedly:
Tell Martha not to moan! Now we're at the grave of Lazarus, comforting his sisters Mary and Martha: have no fear, the One is coming who will raise your brother from the dead--and to prove why we're so sure of this, we sing:
'cuz Pharaoh's army's been drown in the sea!
Now we're back with Moses, witnessing God rescue his people from their captors--a meaning which has been realized in this song as beyond political implication: a symbol of God defeating death itself.
All of these things are happening at once in the tune: a blinding flash of poetry, theology, history, and musical praise. Without once saying the name of Jesus, the spiritual is all about Him: the entire history of salvation as demonstrated on the national, personal, and existential level.
My favorite studio version is the one recorded by Take 6 back in 1988.
They've done countless great live versions too: here's one from 1990 (check out the extended modulating coda).
God Bless you all this Holy Week.