I have a sentence along the lines of
The heading reads, "a chart heading."
The comma seems a bit awkward to me, but I cannot seem to find any explicit guidance in the Chicago Manual of Style on whether or not it should be there, and a couple of searches of CMoS's Q&A find instances both with and without the comma (and a number of instances with a colon instead of the comma).
Is this better with or without the comma? Why?