This quotation comes at the end of an addendum the lawyer supposedly added to the story. In it, he tells of a rumor that Bartelby had been fired from a job at the dead letter department in the Post Office. Evidently, it was his job to sort through letters that could not be delivered. As he would sort through the letters just before they were burned, he would often find things like rings, or money desperately needed by someone who never received it. The constant shuffling of the letters which would never reach their intended destination, along with some of the items contained in those letters, eventually made Bartelby very depressed. That depression ultimately lead to his death. At the end of the story, the lawyer seems to offer a prayer for Bartelby and those like him who are forced to do thankless jobs day and day and eventually go mad because of their job. He says,
". . .pardon for those who died despairing; hope for those
who died unhoping; good tidings for those who died stifled by unrelieved calamities. On errands of life, these letters speed to death.
Ah Bartleby! Ah humanity!"
The lawyer seems to be asking for some understanding for Bartelby as well as for those among humanity who suffer the same fate. Thus, this is Melville's way of making Bartelby's story more universal. Using the lawyer as his voice, he points out that other often suffer the same fate as Bartelby and like, Bartelby, die unnoticed and unmourned.