Thought experiment

Imagine it is 600 years from now.

There has been a long period of wars, diseases, migrations and natural disasters all over the planet, libraries were destroyed, the internet was lost through cyber attacks, major solar flairs and other unknown causes. Books from secret private collections have fallen apart or were used as fuel for people to warm themselves or to cook on. Most people could no longer read them anyway, since for a few hundred years education was no priority. Also, because of a dogmatic ideological system that has ruled for several centuries, it was forbidden to own information carriers from before 2500 CE. Many other dreadful things have happened as well that I will not describe.

But now there is relative peace again and a Dutch text fragment from +/- 1900 CE is found. It contains the following expression:

"Ledigheid is des duivels oorkussen"
(proverb: "the devil finds work for idle hands", literally: "idleness is the devil's ear-pillow")

A researcher has a rare dictionary from the year 2400 CE. He starts translating and interpreting.

He can not find the word "ledigheid" (which even in 2000 CE was old fashioned, rarely used Dutch for idleness). But he does find "lenigheid", which means limberness. So he assumes a typing error and that limberness was meant.

"Is" is easy, but "des duivels" may not be recognized as a genitive case. In that case it may be misread as plural "the devils".

Since "oorkussen" is not in his dictionary, but "oor" and "kussen" are, he assumes that a space was missing. "Oor" means "ear" and "kussen" can mean the verb "to kiss" or the noun "pillow". "Oorkussen" for pillow already was out of use in 2000 CE. So he decides for "to kiss ear" or "earkissing".

"Limberness is the devils earkissing" or "limberness is to kiss ear (of/by?) the devils".

It does not make sense to him but, since he does not like to admit that he does not know, he decides to interpret it as:

"One needs to be flexible to kiss the ears of devils."

He concludes that it must be a joke.

~ ~ ~

This is how some fragments of the OLB were translated by Ottema in 1872, although he did not draw the conclusion that the text had to be a joke.

That is what Jensma did, who made some things even worse in 2006 with (subsidized and "scientifically sound"!) translations like:

GÉRT.PIRE.HIS TOGHATER (p.72 of manuscript)
"Gertje, de dochter van Grote Pier"
(Little Gert, daughter of Great Pier [= Pier Gerlofs Donia (c.1480 - 1520)])

and:

ALLERA MANNALIK THÉR EN OTHER  FON SINE FRYDOM BIRAW [...]
MOT IK ANDA BARN.TAM ÉNER SLAFINE FARA LÉTA. (MS p.12)
"Alleman die een ander van zijn vrijheid berooft [...] 
moet ik in de baarmoeder van een slavin laten voeren"
(anyone who robs another's freedom [...]
I'll have to lead into the womb of a slave girl).