"What is the sorriest thing that enters Hell?
None of the sins, -- but this and that fair deed
Which a soul's sin at length could supersede.
These yet virgins, whom death's timely knell
Might once have sainted. . ."
In light of his wife's death, Rossetti is concerned with the judgement of good and evil. He laments how even a horrible person does some good, which appears to go to waste if that person winds up in hell. He views hell as a lottery, a chance encounter for the incomplete person. If given more time, perhaps that person would have been sent to the other place. This question implies a resentment of his wife's early passing.
"Lo! how the little outcast hour as turned
And leaped to them and in their faces yearned: --
'I am your child: O parents, ye have come!"
Rossetti compares death to the child which he and his wife never had together. When he arrives, he greets them by name, familiarly. He believed he was unwelcome, but he arrives anyway. This comparison illuminates Rossetti's own feeling of incompletion and his fear of time's solemn forward march.
“Look in my face; my name is Might-have-been;
I am also call'd No-more, Too-late, Farewell”
The despair in this excerpt is clear. Rossetti suffers from severe anger at his wife's death. He views all of life as a waste in light of this one revelation -- everyone dies, without their consent. Death doesn't wait. In his frustration, Rossetti sees himself as doomed, death's victim already though he looks alive.
"Love's throne was not with these; but far above
All passionate wind of welcome and farewell"
Rossetti explores all the mind's depth, through various emotion and conceptions of God. He concludes that none of these ideas fulfill the role of love. He finds love above, far distanced from himself. In suffering -- passion -- alone, in the balance of coming and going, he finds love. It is a sort of acceptance of one's own impotence.
