This is also the name of a fable by G.E.Lessing. An (approximate!) English translation is below.

    Ein Esel begegnete einem hungrigen Wolfe. "Habe Mitleiden mit mir," sagte der zitternde Esel; "ich bin ein armes, krankes Thier; sieh' nur, was für einen Dorn ich mir in den Fuß getreten habe!"
    "Wahrhaftig, du dauerst mich" verseßte der Wolf. "Und ich finde mich in meinem Gewissen verbunden, dich von diesen Schmerzen zu befreien."-
    Kaum war das Wort gesagt, so ward der Esel zerrissen.



    An Ass met a hungry wolf. "Have compassion on me," said the trembling ass; "I am a poor, sick animal; do but see what a thorn I have run into my foot!"
    "Truly, you move me to pity," rejoined the wolf. "And I find myself bound by my conscience to deliver you from this pain."-
    Scarcely was the word said, than the ass was torn to pieces.