Both Gibran's "Song of the Rain" and Wordsworth's "I Wandered Lonely as a Cloud" celebrate nature and are told by a first person narrator.
The two poems, however, are also different. Gibran's speaker is the rain, which likens itself to "beautiful pearls" and describes itself as a "messenger of mercy," a cooling balm to a hot earth, and a "welcome song."
Wordsworth's speaker is the poet himself, a human being. He compares himself to a lonely cloud, just as the rain compares itself to other objects; but Wordsworth's speaker primarily focuses on what he sees around him, rather than on his own virtues. He becomes joyful and elated, his sad mood swept away, when he sees thousands of daffodils swaying in the breeze in front of a lake. Later this memory will provide him with joy as he lies on his couch and remembers the spring scene.
Rather than becoming elated by nature, Gibran's rain brings joy to others. It quenches thirst and helps heal people. At the end of the poem, the rain compares itself to love: both sigh from affection, laugh from joy, and shed tears at remembering loved ones.
The theme of Gibran's poem is the many positive attributes of rain; the theme of Wordsworth's poem is the joy nature can bring. Both works, therefore, emphasize the good to be found in the natural world. Gibran's poem, however, focuses only on the good aspects of nature, while Wordsworth's poem reminds us of the power of memories of natural scenes to solace us.