Az-Zukhruf 43:33

Walawla an yakoona annasuommatan wahidatan lajaAAalna liman yakfuru birrahmanilibuyootihim suqufan min fiddatin wamaAAarijaAAalayha yathharoon

And if it were not that the people would become one community [of disbelievers], We would have made for those who disbelieve in the Most Merciful - for their houses - ceilings and stairways of silver upon which to mount.

Were it not that all people would become of a single creed (i.e. disbelief), We would have caused, for those who disbelieve in RaHmān, roofs of their houses to be made of silver, and the stairs as well, on which they would climb,