Surah Al-An'am Ayah 19

قُلۡ أَيُّ شَيۡءٍ أَكۡبَرُ شَهَٰدَةٗۖ قُلِ ٱللَّهُۖ شَهِيدُۢ بَيۡنِي وَبَيۡنَكُمۡۚ وَأُوحِيَ إِلَيَّ هَٰذَا ٱلۡقُرۡءَانُ لِأُنذِرَكُم بِهِۦ وَمَنۢ بَلَغَۚ أَئِنَّكُمۡ لَتَشۡهَدُونَ أَنَّ مَعَ ٱللَّهِ ءَالِهَةً أُخۡرَىٰۚ قُل لَّآ أَشۡهَدُۚ قُلۡ إِنَّمَا هُوَ إِلَٰهٞ وَٰحِدٞ وَإِنَّنِي بَرِيٓءٞ مِّمَّا تُشۡرِكُونَ ١٩

Qul ayyu shayʾin akbaru shahādah, qulillāh, shahīdum baynī wa baynakum, wa ūḥiya ilayya hādhal-qurʾānu liʾundhirakum bihī wa mam balagh, aʾinnakum latashhadūna anna maʿallāhi ālihatan ukhrā, qul lā ashhad, qul innamā huwa ilāhuw wāḥiduw wa innanī barīʾum mimmā tushrikūn.

Say, "What thing is greatest in testimony?" Say, "Allāh is witness between me and you. And this Qur’ān was revealed to me that I may warn you thereby and whomever it reaches.¹ Do you [truly] testify that with Allāh there are other deities?" Say, "I will not testify [with you]." Say, "Indeed, He is but one God, and indeed, I am free of what you associate [with Him]."

Translation: Sahih International