If one used only biblical writings, then one could simply set a low standard as evidence of the signature.
If one uses writing that it is absolutely agreed is not of divine origin (anything by Gore Vidal, for example :>), then one would have a baseline for comparing with recognized divine writings.
ABsolutely.
And, supposedly such challenges have not been met for decades.
Would be great to have some of the naysayers try.
Results obtained from non-biblical literature would merely confirm it as non-biblical and sets an artifically low bar for a test of 'divinely inspired' (as opposed to a concordance or commentary for example) biblical literature to meet. The only divinely inspired biblical literature I know of, is the bible.
We already know the bible contains many instances of '7', '40', '1000' for example, whereas non-biblical literature does not have that same proportion. If something non-biblical were then used as part of a 'control' sample, it's lack of occurrances of instances of '7', '40', '1000' would by contrast make such instances in the bible stand out more, when we know they are normal and not hidden.
Those instances of '7', '40', '1000' in the bible are there in plain text by God's inspired writing, not secretly hidden in the text letter sequences and man's chapter/verse boundaries. But a flawed control having no instances of '7', '40', '1000' would leave the impression of the bible being encoded in ways God did not encode it.
Did that make sense?
The bible is unique and we must be careful how we compare it to other literature, especially if the purpse of our comparison is to form conclusions about how God wrote the bible.