Walt Whitman’s Mystical Experience in Song of Myself

I read this poem in Leaves of Grass ten years ago and have never stopped thinking about this one part:

Swiftly arose and spread around me the peace and knowledge that pass all the argument of the earth,
And I know that the hand of God is the promise of my own,
And I know that the spirit of God is the brother of my own,
And that all the men ever born are also my brothers, and the women my sisters and lovers,
And that a kelson of the creation is love,
And limitless are leaves stiff or drooping in the fields,
And brown ants in the little wells beneath them,
And mossy scabs of the worm fence, heap’d stones, elder, mullein and poke-weed.