Q: Who can confirm that a rhetorical question is a poetic device?
A: No one can confirm that a rhetorical question IS a poetic device.
A rhetorical question CAN be a poetic device, but a rhetorical question IS NOT JUST a poetic device.
If you say “Is a rhetorical question a poetic device?” the answer would be “it could be, sometimes, maybe, depending,” most definitely.
If you are asking for someone to give you an example of a poetic text based on a rhetorical question, I am too tired for higher complexity that the following:
Nature, that great reward, when left alone, don’t you find it so?
If I just did your homework, buy me a coffee