Dalil

Quran Fussilat 41:3

كِتَٰبٞ فُصِّلَتۡ ءَايَٰتُهُۥ قُرۡءَانًا عَرَبِيّٗا لِّقَوۡمٖ يَعۡلَمُونَ

Translation

A Book whose verses have been detailed, an Arabic Qur’ān for a people who know,