I'm reading "A Roadside Stand" by Robert Frost, which you can read online. Below I have given the particular paragraph.
In the line -
To put these people at one stroke out of their pain
Robert Frost wants to kill the country people at one stroke to relieve their pain.
However, in the line -
And offer to put me gently out of my pain
he asks the reader to put him 'gently' out of his pain.
What does he particularly mean by 'gently' here? Does he mean 'slow death'? How could we put him 'gently' out of his pain?
No, in country money, the country scale of gain,
The requisite lift of spirit has never been found,
Or so the voice of the country seems to complain,
I can't help owning the great relief it would be,
To put these people at one stroke out of their pain.
And then next day as I come back into the sane,
I wonder how I should like you to come to me
And offer to put me gently out of my pain.