[1rudeboy]

That's the point: poets intend their punctuation to be a cue for the reader (it's not a matter of grammar).

I don't feel like pulling out all of my print versions of this poem, but I'll wager that there is no comma there because Frost didn't want one there.

[Tax-chick]

I have not read this in a book for a long time. I think it’s in the poetry unit of my son’s literature course from last year, because I remember his asking me about it.