The poem sets two kinds of strength against each other. In the first two lines, the speaker imagines a time when the ground is "reinforced with concrete," and says the "base of glass" will then become obsolete. Glass is clear but fragile, so it seems to stand for a delicate, easily broken way of living or feeling. Concrete is solid and dependable, a stronger footing that will replace it.
The last two lines turn toward something gentler. "A drop of hope can heal the broken," the speaker says, and a "little word" can "swallow our past whole." Small things, a drop and a word, are given surprising power. The image of swallowing the past is a bit ambiguous: it could mean forgiveness and relief, or it could mean burying what hurt us.
The mood is quietly optimistic, with a hint of wariness. The title, "June – Sunrise," adds a feeling of fresh beginnings. Judging by the imagery, the speaker believes that a new start comes less from hard structures than from small acts of kindness and hope.