I'm a little puzzled by the use of "it" rather than "him", but I think it means that just as the canopy of the elm does not droop down, but remains graciously aloft, so the good man remained gracious but did not stoop down to the level of the suitor. In this context sentence I would usually understand the good man not "stooping" to indicate that the suitor was his inferior. However, the preceding text seems to suggest that the suitor was physically shorter than him as well as being his inferior, so I guess there's a dual meaning.
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