For an English Lit. essay I am writing on TS Eliot and Joyce, I wish to use a Biblical quotation I find useful in illuminating certain themes common to their work (1 Corinthians 13 if anyone is interested---I think the ideas about love/charity, growth from childhood to adulthood and some of its metaphors are highly applicable).
However, I lack the word for such a quotation; I have considered "epigraph," "citation," "touchstone" and "reference point," however none of these seem entirely apt. Rather than positioning the quotation as an epigraph, I would prefer to introduce it in the actual essay itself. I would use it in the context something like the following: "to explain Eliot's metaphor, I cite 1 Corinthians 13 as a (blank)."
I am not sure if there is a precise word, however I will be grateful to any suggestions!