Following Ancestral Religion

Or have We given them a book before the Qur'an to which they are adhering?

Rather, they say, "Indeed, we found our fathers upon a religion, and we are in their footsteps [rightly] guided."

And similarly, We did not send before you any warner into a city except that its affluent said, "Indeed, we found our fathers upon a religion, and we are, in their footsteps, following."

[Each warner] said, "Even if I brought you better guidance than that [religion] upon which you found your fathers?" They said, "Indeed we, in that with which you were sent, are disbelievers."