Allāh has sent down the best statement: a consistent Book wherein is reiteration. The skins shiver therefrom of those who fear their Lord; then their skins and their hearts relax at the remembrance [i.e., mention] of Allāh. That is the guidance of Allāh by which He guides whom He wills. And one whom Allāh sends astray - for him there is no guide.

Sahih International