Surah Al-A'raf 7:52

وَلَقَدْ جِئْنَـٰهُم بِكِتَـٰبٍ فَصَّلْنَـٰهُ عَلَىٰ عِلْمٍ هُدًى وَرَحْمَةً لِّقَوْمٍ يُؤْمِنُونَ

And We had certainly brought them a Book which We detailed by knowledge - as guidance and mercy to a people who believe.

Translation: Saheeh International

Tafsir

And indeed We have brought them that is the people of Mecca a Book the Qur’ān which We have detailed which We have made clear through tidings and the Promise of reward and the Threat of punishment with knowledge ‘alā ‘ilmin is a circumstantial qualifier in other words ‘knowing what has been detailed in it’ a guidance …

Excerpt from Tafsir al-Jalalayn, commentary on 7:52, via Quran.com. The reader has the full commentary and 9 more tafsirs.