Through the Dark Sod — as Education —

Through the Dark Sod — as Education —
The Lily passes sure —
Feels her white foot — no trepidation —
Her faith — no fear —

Afterward — in the Meadow —
Swinging her Beryl Bell —
The Mold-life — all forgotten — now —
In Extasy — and Dell —
                              F559 (1863)  J392

Victorians made much more use of flowers to convey meaning than we do today. Where we might send roses to indicate love or sympathy, they used dozens of flowers for as many messages. Lilies represented purity, beauty, spirituality and rebirth – associations from hundreds of years before Dickinson's time and ones that continue to this day – just look on Easter altars or in bridal bouquets. Judith Farr, in The Passion of Emily Dickinson, writes that Dickinson presents the lily in this poem "as a metaphor of sensuous spirituality". 

Lily bulb

We can see the sensuousness in the tactile qualities of the poem. The lily grows upward from the bulb through the "Dark Sod", and anyone who has ever gardened knows the feel and smell of such rich earth. "Dark" in this case suggests the richness of the soil but also the subterranean darkness where you must feel your way carefully. Many lily shoots never breach the ground and find the sun; they might encounter dangers in pests or rodents, suffer from bulb mold, be blocked by obstacles or damaged by the roots of other plants.
This lily however, "passes sure" through the tests of her "Education".  We see her emerging from earth to a better, brighter place as if an eternal soul were being born from the flesh of the world. Her "white foot", her bulb, provides the nutrients to fuel her journey. She "feels" its soundness and between her self confidence and her faith in what lies ahead, she ventures forth with "no trepidation". 

Greenish-white, beryl, bell of the lily

Her steady faith and earthly education are rewarded, for in the second stanza we see the lily ecstatic in a beautiful little meadow. This is the second tactile moment, for she isn't just gazing at the sun but "Swinging her Beryl Bell".  

The poem has a far different mood than those where the poet is paralyzed by dread or trying to recover from some staggering blow. The soul in this poem keeps moving and her keystone is faith. The poem is also a significant departure from those poems where the dead languish seemingly forever. Here there is an Education in the dark sod of life, and then there is an "Afterward" where the soul's beauty is completed, where she can swing her flower in "Exstasy". 

The poem echoes the steady confidence of the lily in three spondees: Dark Sod, white foot, and Mold-life. These are key images – the danger of the dark earth, the pure faith and self confidence of the lily/soul, and the mortality of the flesh in its mold-life. The joy of the poem is emphasized with the freedom of "Swinging" and the alliteration of Beryl Bell – further emphasized by the rhyme of "Dell". Heaven here is both a condition, ecstasy, and a location, the dell. This charmed little meadow is as much the rightful heritage of the lily as heaven is for the soul.

It's a simple metaphor, beautifully rendered.