A'nbiyaaa : 25

وَمَآ أَرْسَلْنَا مِن قَبْلِكَ مِن رَّسُولٍ إِلاَّ نُوحِى إِلَيْهِ أَنَّهُ لا إِلَـهَ إِلاَّ أَنَاْ فَاعْبُدُونِ

And We did not send any Messenger before you but We revealed to him (saying): "There is no God but I, so worship Me.

A'mbiyaaa : 25