We weren't joking about there being different versions of Whitman in this poem. You've got to watch out for them.
He tells his soul he believes in it, and that his "other" nature (the one concerned with day-to-day worries) must be kept in its place.
Again he invites the soul to hang out in the grass. He wants the soul to hum a pleasant tune…
…And that's when things get steamy. Whitman talks about having an erotic encounter with his own soul.
They were lying in the grass together in June, when suddenly Whitman's soul gave him the most soulful kiss you can imagine. The kiss reaches all the way to the speaker's heart.
Being intimate with your own soul can only lead to "peace and joy and knowledge."
At the end of the section, we get a flavor of Whitman's religious beliefs. He thinks that God is a part of his own nature and not a separate being. This would have been considered blasphemy by most Christians of his time.
He has an epiphany about the world being limitless and everyone being his brother or sister.
Love is a "kelson of the creation." A kelson is a beam that helps to keep a ship steady. In other words, Whitman is saying that love helps to keep the world steady.