In this poem by Kabir, he speaks about a land where there is no doubt or sorrow. He even says so explicitly in the second verse:
(...)"There is a land where no doubt nor sorrow have
rule:
where the terror of Death is no more."(...)
This poem is a metaphor of heaven, God, and an angel or soul (ancient and timeless) represented by the swan. The speaker wants to know where the soul goes when one dies, what it wants, what's the purpose of life. There is a connection to God that brings the soul joy and happiness. It also makes it feel sure about the existence of God and existing forever.