Here's how
Marcus J. Borg explains away all the magic of the metaphor, "My love is a red, red rose":
"My beloved is not a rose, unless I am literally in love with a flower. Rather, there is something about my beloved that is like a rose."
Gee, thanks, Mr. Borg.
Meanwhile, against all odds, my own beloved is an entire bouquet (long-stemmed).
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Chris writes:
Of course, the lyric is "My love is *like* a red, red rose [that's newly sprung in June]"... which makes the exegesis extra redundant.