Cryptanalysis

Hi,

I have been looking at it for a moment and, as I understand it, the sentence "There is a great necessity Get it (them) condemned if possible" is already the deciphered text?
The cipher text should be a list of 5-letters long words

To take the exemple in the codebook: "There is a favourable change in the market in consequence of small supplies coming to hand" is encoded into Maundering, Congress and Supperless which respective codes are 08561, 03514 and 13923. (We only have encoded here). Then we choose the cipher key, e.g. "CUMBERLAND" and we use each digit of our codes to index the cipher key: 08561 -> daerc

The encrypted result is "daerc dmecb cmnum". I would like to confirm that there is no error? If there is none, then could someone explain me want I did not understand here?

Also, I don’t have any clue where a number would be useful (I am refering to the second hint with the arithmetic operation on dates)

Thank you for your support.

Just after writing it, I realized that maybe the ciphering wasn’t following exactly the codebook, especially the ciphering part.
Hint: hopefully I did the "Shift Cipher" a few hours before this challenge.