َ إِلَّا الَّذِينَ آمَنُوا وَعَمِلُوا الصَّالِحَاتِ فَلَهُمْ أَجْرٌ غَيْرُ مَمْنُونٍ ﴿۶﴾ فَمَا يُكَذِّبُكَ بَعْدُ بِالدِّينِ ﴿۷﴾ أَلَيْسَ اللَّهُ بِأَحْكَمِ الْحَاكِمِينَ ﴿۸﴾

﴾6﴿ Ill-lal lazeena aamanoo wa 'amilus saalihaati; falahum ajrun ghairu mamnoon
﴾7﴿ Fama yu kaz zibuka b'adu bid deen
﴾8﴿ Alai sal laahu bi-ahkamil haakimeen

﴾6﴿ Except for those who believe and do righteous deeds, for them is a never-ending reward
﴾7﴿ So what causes you to deny the Judgment after this
﴾8﴿ Is not Allah the best of judges

[6] In this, the second type of person is mentioned—those who remain firm upon the natural religion (fitrah). Glad tidings are given to them, and their qualities are described as faith and righteous deeds.
[7] This is a conclusion based on the previously mentioned signs of Allah’s power, intended to prove the Day of Judgment. That is why the particle fa (so) is used—meaning: the same Allah whose power is clearly shown through the examples of the fig, the olive, Mount Sinai, the secure city (Makkah), and the creation of man, all divided and explained—has the ability to resurrect after death and to deliver reward and punishment.
So what justification remains for the deniers to reject it?
[8] This is a clear affirmation of the claim of Tawḥīd (Oneness of Allah), which was previously alluded to in ahsani taqwīm (the best form). It is a refutation of shirk (associating partners) in both control and judgment. The word ḥukm (judgment) here is general—it includes both takwīnī rulings (universal decrees and control over creation) and tashrī‘ī rulings (legislative and religious laws). Both are exclusive attributes of Allah. This attribute of Allah is also mentioned in Surah Hūd (11:45). The word aḥkam (the best of judges) implies that every ruling and act of Allah is perfect, unchallengeable, and beyond objection. No one can oppose His decree or claim authority over Him. And in a hadith narrated by Abu Hurayrah (may Allah be pleased with him) in Tirmidhi, it is reported that when someone recites Surah At-Tīn and then reaches “Is not Allah the best of judges?” (alaysa Allahu bi-aḥkami al-ḥākimīn), he should say: “Bala wa anā ‘alā dhālika mina ash-shāhidīn” — “Yes, and I am among those who bear witness to that.”