Sung by Ofra Haza-- and personally, one of my favorite moments in animation history. I love it. From the movie 'Prince of Egypt.' If you haven't seen it yet, you have to!
EDIT:
LYRICS
Hush now, my baby
Be still, love, don't cry
Sleep as you're rocked by the stream
Sleep and remember my last lullaby
So I'll be with you when you dream
River, o river
Flow gently for me
Such precious cargo you bear
Do you know somewhere
he can live free?
River, deliver him there.