In the poem “Crossing the Bar” by Alfred Lord Tennyson, the sunset and the star symbolize the passage of life and death. The sunset represents the end of life on earth, while the star represents the eternal and infinite nature of the afterlife. The speaker in the poem is asking to be guided across the bar, which is a nautical term for the sandbar at the mouth of a harbor that must be crossed in order to reach the open sea. In this context, the bar represents the barrier between life and death, and the speaker is asking to be guided safely across this threshold. The imagery of the sunset and the star serves to convey the idea that death is not an end, but rather a new beginning, and that the soul will continue on to a higher and more eternal existence.