"Is not Allah most knowing of the grateful?" meaning: the monotheists. Surah al-An'am, from verse (54) to verse (55).
﴿أَلَيْسَ الله بِأَعْلَم بِالشَّاكِرِينَ﴾ يَعْنِي: الْمُوَحِّدين. سُورَة الْأَنْعَام من الْآيَة (٥٤) إِلَى الْآيَة (٥٥).