Surah Al-An'am 6:114

أَفَغَيْرَ ٱللَّهِ أَبْتَغِى حَكَمًا وَهُوَ ٱلَّذِىٓ أَنزَلَ إِلَيْكُمُ ٱلْكِتَـٰبَ مُفَصَّلًا ۚ وَٱلَّذِينَ ءَاتَيْنَـٰهُمُ ٱلْكِتَـٰبَ يَعْلَمُونَ أَنَّهُۥ مُنَزَّلٌ مِّن رَّبِّكَ بِٱلْحَقِّ ۖ فَلَا تَكُونَنَّ مِنَ ٱلْمُمْتَرِينَ

[Say], "Then is it other than Allāh I should seek as judge while it is He who has revealed to you the Book [i.e., the Qur’ān] explained in detail?" And those to whom We [previously] gave the Scripture know that it is sent down from your Lord in truth, so never be among the doubters.

Translation: Saheeh International

Tafsir

The following was revealed when they asked the Prophet s to appoint an arbiter between him and themselves. Say Shall I seek demand other than God as a judge an arbiter between you and me when it is He Who revealed to you the Book the Qur’ān clearly explained? wherein truth is distinguished from falsehood. …

Excerpt from Tafsir al-Jalalayn, commentary on 6:114, via Quran.com. The reader has the full commentary and 9 more tafsirs.