Arise fair sum and kill the envious moon who is already sick and pale with grief meaning?

This line from Shakespeare's "Romeo and Juliet" portrays Juliet's desire for Romeo to be transformed into daylight so he can do away with the darkness of the night, symbolized by the moon's envious and sorrowful presence. It conveys Juliet's longing for Romeo to overcome barriers and bring an end to their feuding families' strife.