Az-Zumar 39:23

Allahu nazzala ahsana alhadeethikitaban mutashabihan mathaniya taqshaAAirruminhu juloodu allatheena yakhshawna rabbahum thummataleenu julooduhum waquloobuhum ila thikri Allahithalika huda Allahi yahdee bihi man yashaowaman yudlili Allahu fama lahu min had

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.

Allah has sent down the best discourse, a book containing subjects resembling each other, mentioned again and again, shivered from which are the skins of those who have awe of their Lord. Then, their skins and their hearts become soft enough to tend to the remembrance of Allah. This is the Guidance of Allah with which He brings to the right path whomsoever He wills. As for the one whom Allah lets go astray, for him there is no one to guide.