Consonance is used throughout the poem to add emphasis to certain moments and simply intensify the poem's language. Take the poem's first line, for example, where /v/, /l/, and /d/ sounds lend a deep, soothing resonance as the speaker describes the mystery and excitement of his love:
somewhere i have never travelled,gladly beyond
The poem in general features many delicate and smooth sounds, which reflects the fact that this is a poem about deep, all-encompassing love.
The poem also turns to sibilance (in the form of both /s/ and /z/ sounds) at times to create a soft hush, quieting the speaker's language in a way that reflects both his reverence for his beloved and this person's fragility. Note the flurry of /s/ and /z/ sounds in stanza 2, for instance, which pair with /l/ sounds to create an intensely soothing passage (despite the fact that the speaker is talking about his beloved's immense hold over him):
your slightest look easily will unclose me
though i have closed myself as fingers,
you open always petal by petal myself as Spring opens
(touching skilfully,mysteriously) her first rose
The poem is filled with moments like this (in part due to the frequent repetition of some form of the word "close"), and thus feels gentle and lovely throughout.
A particularly striking moment of consonance—more specifically alliteration—comes in lines 14-15:
[...] whose texture
compels me with the colour of its countries,
The hard /c/ sounds here add a sense of "texture" to the description of the beloved's fragility.