Whitman says that he is the poet of both the body and the soul.
He challenges the religious concepts of heaven and hell, saying that he has made heaven part of his present life, and that the idea of hell needs to be "retranslated." We get the sense that he's not very keen on traditional Christian notions of hell and punishment.
Oh, and by the way, he loves women and mothers. Always nice to give props to the moms out there.
He's tired of people being modest and insecure. His song is a song of "pride" and celebration. He recognizes that his attitude is new and unusual, but he thinks people need to get over their individual anxieties.
Switching gears, he describes the night, the earth, and the sea in glowing and beautiful terms. The earth has shown him love, so he's going to love the earth right back.
Now, this section changed between the1855 edition of Leaves of Grass and later versions.
In the 1855 edition, the section ends with the lines: "Thruster holding me tight and that I hold tight! We hurt each other as the bridegroom and the bride hurt each other!"
In other words, Whitman is having sex with the earth. No joke. It sounds pretty steamy, but also violent.
These lines were majorly controversial in Whitman's day, and he eventually removed them. We think they belong in the poem. Nothin' wrong with a little love between man and the earth.