Surah Fussilat Tafseer

كِتَابٌ فُصِّلَتْ ايَاتُهُ

A Book whereof the Ayat are explained in detail,

means, its meanings are clear and its rulings are sound and wise.

قُرْانًا عَرَبِيًّا

a Qur'an in Arabic,

means, because it is a clear Arabic Qur'an, its meanings are precise and detailed and its words are clear and not confusing.

This is like the Ayah:

كِتَابٌ أُحْكِمَتْ ءايَـتُهُ ثُمَّ فُصِّلَتْ مِن لَّدُنْ حَكِيمٍ خَبِيرٍ

(This is) a Book, the Ayat whereof are completed, and then explained in detail from One (Allah), Who is All-Wise Well-Acquainted. (11:1)

meaning, it is miraculous in its wording and in its meanings.

لااَّ يَأْتِيهِ الْبَـطِلُ مِن بَيْنِ يَدَيْهِ وَلَا مِنْ خَلْفِهِ تَنزِيلٌ مِّنْ حَكِيمٍ حَمِيدٍ

Falsehood cannot come to it from before it or behind it, (it is) sent down by the All-Wise, Worthy of all praise. (41:42)

لِّقَوْمٍ يَعْلَمُونَ

for people who know.

means, this clear style will be readily understood by scholars who are thoroughly versed in knowledge