﴿ كِتَٰبٌۭ فُصِّلَتْ ءَايَٰتُهُۥ قُرْءَانًا عَرَبِيًّۭا لِّقَوْمٍۢ يَعْلَمُونَ ﴾

“a divine writ, the messages whereof have been clearly spelled out as a discourse in the Arabic tongue for people of [innate] knowl­edge,”

Please check ayah 41:5 for complete tafsir.