A philosopher asked R Gamaliel: It is written in your Torah: FOR
THE LORD THY GOD IS A DEVOURING FIRE, A JEALOUS
GOD (Dt 4:24). But why is He so jealous of its worshippers, rather than of the idol
itself? He said: I
will parable to you a parable.
Unto what is the matter like? It is like a king of flesh and blood
who had a son, and the son reared a dog to
which he attached his father's name, so that
whenever he took an oath he exclaimed: By the life of this dog, my
father! When the king heard of it, with whom is he angry – his son or the dog? Surely he is angry with his son!
B Aboda Zara 54b