Hardest Puzzle: Please Help

[stuartTheClairvoyant]

This puzzle was impossible for me: XGNO LO QHKSY, JWR. XGNO OHY LO QHKSY, JWR.
source: Unattributed.
I had an idea but couldn't get JWR
This puzzle is the hardest that I've ever seen.

[montyb]

Stuart, try “When in doubt, ask. When not in doubt, ask.”

[pickleball]

and that is exactly what Stuart did haha enjoy!!

[stuartTheClairvoyant]

Montyb:

Thank you. I actually got "When in doubt, ..." When not in doubt, ...". Given the structure of the puzzle, I had guessed that OHY was probably "not" and then that XGNO was probably "then", which lead to "When in doubt ...". However, I just couldn't think of what the last word JWR was, although now it seems obviously.

Pickbleball: You are so right!

Thank you all.