Surah Ghafar (The Forgiver), Verse 12

ذٰلِكُمْ بِاَنَّهٗۤ اِذَا دُعِیَ اللّٰهُ وَحْدَهٗ كَفَرْتُمْ وَاِنْ یُّشْرَكْ بِهٖ تُؤْمِنُوْا فَالْحُكْمُ لِلّٰهِ الْعَلِیِّ الْكَبِیْرِ ۟

Zaalikum bi annahooo izaa du'iyal laahu wahdahoo kafartum wa iny yushrak bihee tu'minoo; falhukmu lillaahil 'Aliyyil Kabeer

“(The answer will be:) "This is because, when Allah was invoked as the Only (object of worship), ye did reject Faith, but when partners were joined to Him, ye believed! the Command is with Allah, Most High, Most Great!"”

Quran 40:12 (Yusuf Ali Translation)