Here is part of Salih's story in the Qur'an;
Surah 7:73
To the Thamud people (We sent) Salih, one of their own brethren: He said: "O my people! worship Allah: ye have no other god but Him. Now hath come unto you a clear (Sign) from your Lord! This she-camel of Allah is a Sign unto you: So leave her to graze in Allah's earth, and let her come to no harm, or ye shall be seized with a grievous punishment.
Now compare this to the following;
Surah 5:103
It was not Allah who instituted (superstitions like those of) a slit-ear she-camel, or a she-camel let loose for free pasture, or idol sacrifices for twin-births in animals, or stallion-camels freed from work: It is blasphemers who invent a lie against Allah; but most of them lack wisdom.
Surely this is a contradiction!
.