Surah An-Nisa, ayah 105

4:105

إِنَّآ أَنزَلۡنَآ إِلَيۡكَ ٱلۡكِتَٰبَ بِٱلۡحَقِّ لِتَحۡكُمَ بَيۡنَ ٱلنَّاسِ بِمَآ أَرَىٰكَ ٱللَّهُۚ وَلَا تَكُن لِّلۡخَآئِنِينَ خَصِيمٗا ١٠٥

Innā anzalnā ilaykal-kitāba bil-haqqi litahkuma baynan-nāsi bimā arākallāhu walā takul lil-khā'inīna khasīmā

Indeed, We have revealed to you, [O Muḥammad], the Book in truth so you may judge between the people by that which Allāh has shown you. And do not be for the deceitful an advocate.