A colon is a hard stop like a period, so it causes the reader to pause at the end of line 2. This pause gives the reader the opportunity to dwell on the clause that comes before it: "Your eyes have their silence." The silence, or white space, at the point of the colon mirrors the silence of the beloved's eyes. The pause also introduces the poem's theme, which the speaker expresses in the couplet following the colon:
In your most frail gesture are things which enclose me,
or which i cannot touch because they are too near.
The poet's theme or message is the power of the beloved's fragility. This is an oxymoron
, or seeming contradiction, a literary device which dominates the rest of the poem. The speaker is intensely in love and thus held captive by the frailness of the beloved.
This delicacy, which is likened to petals of the first rose blooming in spring or the delicate quality of snow, intoxicates and overpowers the speaker in a way raw force cannot. As he puts it,
Nothing which we are to perceive in this world equals
the power of your intense fragility.
Once again, paradoxically, the lover's power comes from her weakness.
The second line is the only place in the poem the speaker uses a colon. However, although the poem seems to break off suddenly, unfinished, without any punctuation, in opposition to the hardness of the colon, ending on the image of the lover's "small hands," it shows structure in returning to the beloved's eyes in the final stanza: they are what the speaker understands. Whether he uses punctuation or not, the speaker is held primarily by these eyes.