Final answer:
The repeated cries for rest and the portrayal of water as endlessly crying in 'A Voice on the Wind' embody the voice's weariness and exhaustion.
Step-by-step explanation:
The lines from the poem A Voice on the Wind that best suggest the voice in the poem is weary and exhausted can be found at the beginning and throughout the poem:
The voice of my heart in my side or the voice of the sea,
O water, crying for rest, is it I, is it I?
All night long the water is crying to me.
The repeated cries for rest, the personification of the water as crying, and the lament that rest will never come until "the last moon droop and the last tide fail" evoke a deep sense of weariness and exhaustion. The comparison to the unresting water, which cries throughout the night, underlines the relentless and unfulfilled desire for rest that the speaker feels. The acoustics developed in these lines create the feel of a burden, emphasizing the weary tone.