كِتَابٌ فُصِّلَتْ آيَاتُهُ قُرْآنًا عَرَبِيًّا لِّقَوْمٍ يَعْلَمُونَ
[this is] a Book whose signs have been elaborated for a people who have knowledge, an Arabic Quran,
Agha Ali Puya Commentary
Commentary on Quran 41:3
[Pooya/Ali Commentary 41:3] (see commentary for verse 2)