Loving with restraint is the key to long-lasting love.
<em>"Therefore love moderately; long love doth so;"</em>
As the whole play portrays apassionate love tends to not last, that is why he states that love should be meant to last, then it shouls be rationed.
Explanation:
In each stanza, every other line rhymes (which gives us a Rhyme Scheme of ABAB CDCD EFEF GDGD)
Who's Elisa, and what book and/or passage are you reading? Nobody can answer without that context.