Nineteen years is a long time to love someone, and Levertov squeezes all of it into one sentence. There is no full stop between "Somehow" and "tree." Conception, birth, childhood and adulthood rush by in a single breath, as if the speaker, a mother looking at her grown son, can no longer separate the stages. The poem is about the moment a parent realises that the baby she carried has become a person entirely outside her. Its central idea is that this is a second birth, and perhaps the harder one.
The opening is unsentimental. "Somehow" admits she doesn't quite understand how it all happened, and "clumsily passionate" is an honest, faintly comic way to describe conception, a long way from greeting-card tenderness. The speaker is also the one acting: "I drew into me the seed of a man." Then come two curt verbs, "and bore it, cast it out." "Bore" means both carried and gave birth to, while "cast it out" sounds like a farmer scattering seed but also like banishment. Birth is the first separation, and it is slightly violent. The coined word "man-seed" works in two directions, as the seed of a man and as the seed that will become one.
The middle of the poem is its boldest stretch. "Though I beat him, hurt him, / while I fed him, loved him" is built from two identical pairs, each a one-syllable verb followed by "him." The mirrored grammar sets harm and care side by side. The conjunctions matter too. "Though" and "while" suggest the two happened together rather than one after the other. We can't tell whether "beat" is literal or a figure for the rough struggle of raising a child, but either way the speaker refuses to tidy her motherhood into something gentler than it was. Her confession makes the later admiration more believable.
A small grammatical detail adds to this. The subject of "now stand beyond me" is "subtle mind and quick heart," so what stands apart from her is not his body, which she made, but his thinking and feeling, which she cannot claim as hers. The adjectives are precise. "Subtle" and "quick" praise qualities she did not design and perhaps could not have predicted.
The form helps the meaning. The poem is in free verse, with no rhyme and no regular metre. The first lines are short and abrupt, and the dash hanging after "of a man" gives a catch of breath before the birth verbs. As the sentence moves into the present, the lines lengthen and slow: "beyond me, out in the world / beyond my skin." The repeated "beyond" pushes the son further away with each line, and "skin" names the boundary that once held him. The word "now" is the hinge, where nineteen years of past tense arrive at a pause.
The final image is a simile: he is "beautiful and strange as if / I had given birth to a tree." It echoes the seed of the opening, so the poem closes a circle from seed to tree. A tree grows on its own timetable, is rooted in its own place, and can be admired but not carried or steered. "Strange" is the key word. The most familiar person in the speaker's life has become someone she looks at with something like wonder. The tone is awe rather than grief, and nothing is said about loss. Even so, the impossible birth of a tree hints at how unlikely and unrepeatable the whole experience is.
The title supports this reading. The hyphens turn "He-Who-Came-Forth" into a name, almost like a figure from myth or scripture, as though the son has become larger than an ordinary child. "Came forth" can mean being born, but judging by the poem's final lines it also fits the way he has emerged into adulthood.
What makes the poem significant is its honesty about motherhood. It does not offer a glowing portrait of selfless devotion. It admits clumsiness, cruelty and love at once, and it concludes that the success of that love is shown in the child's separateness. Readers who are on the other side of the relationship, the sons and daughters, may find it just as striking, because it shows what a parent might be thinking while watching them grow away.