The narrator is on his "death-bed" and recognizes that his youth was good and he lived a good life. The "glowing of such fire" seems like it would relate to Hell, but really it refers to the fire and passion of youth, that burns out as people grow older, and is extinguished entirely by the time a person has lived a long life and is ready to die. He recognizes he "must expire," and that his life will be consumed by the joys and youth that nourished it when he was younger. Again, the narrator seems to be reassuring the other person, and telling them that he lived a long and good life, he enjoyed the passions of youth, and that he is now ready to die, and that death is inevitable. This thou perceivest, which makes thy love more strong,

To love that well which thou must leave ere long

These final two lines are probably the most important in the sonnet, because they are telling the person the narrator is talking to that the narrator knows they love him, and that makes their love all the more important or "strong." He also recognizes that this person also understands what he has been trying to say, that he has lived a long, good life, and that he has been loved, and so now, it is time to leave. This understanding, "This thou perceivest," also makes their...

In addition, he acknowledges that he will die soon, but that he has "loved well" and he has no regrets about his life.
Thus, this poem is all about the death of the narrator, but it is also a poem of hope and love, because throughout the poem, the narrator not only confronts his own mortality, he tries to make his death a little less painful for his loved one, so save them grief and fear. While he is the one dying, he is still concerned about the feelings of his family and his loved ones, and so he tries to comfort them even as he lies on his death-bed. This sets this poem apart, because most people confess their sins or confront their fear of dying on their death bed, but this narrator is more concerned about the people that he loves than himself. That is the mark of true and abiding love, and so, while this poem seems to be about death and dying, there is a part of it that is a pure celebration of love, long life, and relationships. The narrator cares more about the other person and their reaction to his death, and that is truly unselfish and kind, making his last act on earth one of kindness, generosity, and most of all, love.