This seems like a pretty simple question, doesn’t it? But let me tell you, it isn’t! I’ve done lots of trolling the internet looking for answers and come across some pretty convoluted ideas, but there seems to be one answer that makes the most sense. The facts that there are several versions of the lyrics and the ideas seem somewhat truncated mark this as a genuine folk song, passed down orally for a number of years.
Before I get to the various meanings for “rock,” here are some ideas that do seem clear. “Comin’ up, Lord,” has to refer to Elijah’s being taken up to Heaven in a fiery chariot. One of the choruses in Mendelssohn’s Elijah also vividly depicts that event. Interesting to compare that composer with his background of wealth, privilege and refinement with the unknown slave who first came up with this spiritual and whose hands were roughened from cotton bolls and back was scarred from the whip. Could the two of them have found common ground if they had ever met? I truly think they could.