Put in a simple (and kind of boring) way, the goal of the first stanza is to prove that "Nothing is so beautiful as spring." But the descriptions of nature in spring also make some subtler claims, among which are: the idea of harmony between man and nature, the way nature can provide a connection between heaven and earth, and the powerful effect spring's beauty can have on people.
- Line 2: The image of "weeds, in wheels" is pretty. But also – because weeds are part of the natural world, while wheels are man-made – by putting the two together, the image becomes a symbol for a harmony of man and nature.
- Line 3: "Thrush's eggs look little low heavens" is a modified simile that connects the idea of heaven to earthly things – specifically these tiny bird eggs. We say "modified simile" because the "like" has been left out. It's not quite a metaphor, because it doesn't say the eggs are little low heavens, but taking out the "like" does nudge it in that direction a little bit.
- Lines 4-5: The powerful effect of the thrush song, which "does so rinse and wring / the ear," is told to us through synecdoche. The ear is used as a stand-in for the person, in his or her entirety, who is listening.
- Line 5: When we're told, still talking about the thrush, that "it strikes like lightnings to hear him sing" we have a simile built into a metaphor. Because the sound doesn't literally strike a person (unless our speaker is talking about sound waves, which we doubt) then "strike" is a sort of implied metaphor, turning the sound into something so physical it can be felt as a strike. But then we have the feeling of that strike further elaborated by the simile of "like lightnings."