Six lines are enough for Whitman to take a love that begins in the body and send it upward until it leaves the body behind. The opening word, "PRIMEVAL," capitals and all, sets the scale. Primeval means belonging to the earliest age of the world, so the speaker's feeling is made to seem older than any single courtship, something elemental that was there at the start. The poem then moves from that deep past to a kind of weightless future, and its central idea is that love, at its fullest, becomes a reality that outlasts the physical self.
Whitman's free verse suits that movement. There is no rhyme and no steady metre, and the lines swell and shrink as the feeling demands. The second line is the longest and most breathless, piling up "O bride! O wife!" before admitting that the love is "more resistless, more enduring than I can tell." The comparatives push against the limits of language, and the line ends on "the thought of you," which suggests this love is felt in the mind as much as in the arms. The repeated "O" is a speaker's cry, close to the sound a person makes when words run out.
The third and fourth lines are the strangest, and the most interesting. "Then separate, as disembodied, the purest born" has no obvious subject, so it is unclear what is separating from what. Perhaps the love detaches itself from the physical, or the speaker detaches from his own body. The line after it is a stack of noun phrases: "The ethereal, the last athletic reality, my consolation." "Ethereal" means airy and almost not there, yet "athletic" belongs to the gym and the running track. Putting the two together insists that the spiritual is not weak or vague. It is strong, muscular, and somehow still a "reality," indeed the "last" one, what remains when everything else has been stripped away. The word "consolation" hints that this comfort is needed, though the poem never says what for.
A reader may notice that up to this point the poem barely moves. Apart from the speaker's statement of love, the first four lines are exclamations and descriptions. The first real action arrives in line five: "I ascend—I float in the regions of your love." The dash makes a small launch pad, and the repeated "I" gives the verbs a quick, rising rhythm. Floating is the opposite of the "resistless" force of line two. The love that was overwhelming is now a place the speaker can drift through, a whole region of air.
Then comes the surprise. The poem began with "the woman I love," and addressed a "bride" and a "wife," but the final address is "O man, / O sharer of my roving life." The beloved has changed gender between the first line and the last. The poem does not explain this, so any reading is an inference. One possibility is that two different voices are speaking, each addressing a different partner. Another is that a single speaker's love is bigger than any category, sliding from "woman" to "man" as it rises out of the body. The word "disembodied" in line three gives some support to that second reading, since once the body is set aside, the labels that depend on it may fall away too. Either way, the shift makes the reader slow down and ask what the poem means by "you."
The last line is short and plain after all that soaring. "Roving" suggests a life of wandering, with no fixed home, and "sharer" makes the beloved a companion on that road rather than a possession. The poem begins in something primeval and ends with two people moving through life together, so the cosmic and the everyday are joined.
What makes the poem worth reading is how much it compresses. It keeps the body and the spirit in the same breath, as in the word "athletic," and it lets love change shape mid-poem without stopping to justify itself. The poem leaves us at the moment of ascent, still floating.