I learned this exactly with one word different the way Lady Thorn posted it. I learned it at YWCA Camp Timbertall in 1954 and I teach it to my singing group, Sing Thing Family Singing, every so often. I, also, do not know where it came from and have no ideas on the matter. I'd love to find out. Nice variable harmonies for each verse. 2 parts, but the harmony changes each verse.