19:97
فَإِنَّمَا يَسَّرْنَـٰهُ بِلِسَانِكَ لِتُبَشِّرَ بِهِ ٱلْمُتَّقِينَ وَتُنذِرَ بِهِۦ قَوْمًا لُّدًّا
fa-innamā yassarnāhu bilisānika litubashira bihi l-mutaqīna watundhira bihi qawman luddan
We have made it easy, in your own language [Prophet], so that you may bring glad news to the righteous and warnings to a stubborn people.
So We have made this (the Qur’ân) easy in your own tongue (O Muhammad صلى الله عليه وسلم), only that you may give glad tidings to the Muttaqûn (the pious - See V.2:2), and warn with it the Ludd (most quarrelsome) people.