"Nothing in the world is single; all things by a law divine"
It is God's Law that everything in nature mingles together, religious language suggest love isn't just natural, it's divine and sacred
Powerful religious imagery reinforces the sense that her submission to him is morally right and virtuous. Shelley's position as an Atheist enables us to interpret this as something slightly more manipulative and unscrupulous
It seems ironic and that, as a passionate lover, he would be prepared to say anything in his quest for a kiss