Book curses

A curse against thieves, written in various middle english books:

Thys boke is one
And Godes kors ys anoder;
They take the ton,
God gefe them the toder.

[This book is one (thing),
And God's curse is another;
They that take the one,
God gives them the other.]

Another one, found in a breviary held in a library in Cambridge:

Wher so ever y be come over all
I belonge to the Chapell of gunvylle hall;
He shal be cursed by the grate sentens
That felonsly faryth and berith me thens.
And whether he bere me in pooke or sekke,
For me he shall be hanged by the nekke,
(I am so well beknown of dyverse men)
But I be restored theder agen

[Wherever I might end up over all,
I belong to the Chapel of Gonville Hall;
He that feloniously ferries me and bears me from thence
Shall be cursed by this great sentence:
Whether he bears me in a pouch or sack,
On account of me he shall be hanged by the neck,
(I'm too well known by many men [to not be noticed])
Unless I be returned there again.]

And as it is surely not my wish to be also cursed ; ), here's the source.