وَمَآ اَنْزَلْنَا عَلَيْكَ الْكِتٰبَ اِلَّا لِتُبَيِّنَ لَهُمُ الَّذِى اخْتَلَفُوْا فِيْهِۙ وَهُدًى وَّرَحْمَةً لِّقَوْمٍ يُّؤْمِنُوْنَ ( النحل: ٦٤ )
Wa maaa anzalnaa 'alaikal Kitaaba illaa litubaiyina lahumul lazikh talafoo feehi wa hudanw wa rahmatal liqawminy yu'minoon (an-Naḥl 16:64)
And We have not revealed to you the Book, [O Muhammad], except for you to make clear to them that wherein they have differed and as guidance and mercy for a people who believe. (An-Nahl  : 64)
1 Mufti Taqi Usmani
We have sent down the Book to you, only because you may explain to them what they differed about, and (so that it may be) guidance and mercy for a people who believe.