16:22
إِلَٰهُكُمْ إِلَٰهٌۭ وَٰحِدٌۭ ۚ فَٱلَّذِينَ لَا يُؤْمِنُونَ بِٱلْءَاخِرَةِ قُلُوبُهُم مُّنكِرَةٌۭ وَهُم مُّسْتَكْبِرُونَ
Your god is one God. But those who do not believe in the Hereafter - their hearts are disapproving, and they are arrogant.
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
None is to be worshipped except Allah
Allah tells us that there is none to be worshipped besides Him, the One, the Unique, the Lone, the Self-Sufficient. He tells us that the hearts of the disbelievers deny that and are astonished by that:
أَجَعَلَ الاٌّلِهَةَ إِلَـهاً وَحِداً إِنَّ هَـذَا لَشَىْءٌ عُجَابٌ
("Has he made the gods (all) into One God! Verily, this is a curious thing!") (38:5).
وَإِذَا ذُكِرَ اللَّهُ وَحْدَهُ اشْمَأَزَّتْ قُلُوبُ الَّذِينَ لاَ يُؤْمِنُونَ بِالاٌّخِرَةِ وَإِذَا ذُكِرَ الَّذِينَ مِن دُونِهِ إِذَا هُمْ يَسْتَبْشِرُونَ
(And when Allah alone is mentioned, the hearts of those who do not believe in the Hereafter are filled with disgust, and when those besides Him are mentioned, behold, they rejoice!) (39:45).