Allah (swt) previously told us about the (vision). Now, He is speaking about the (enlightenment).

(… قَدْ جَاءَكُم بَصَائِرُ مِن رَّبِّكُمْ ) (There has come to you enlightenment from your Lord.…): What is the difference between (enlightenment) and (vision)?

Enlightenment is specifically for the believer. This is because, it is connected to the heart, and it concerns the granting of illuminations and spiritual morale, and the light of morals values do not come except from the heart. As for vision, it is only for the eyes. It is granted to the believer and disbeliever alike, i.e., to all of mankind.

(… فَمَنْ أَبْصَرَ فَلِنَفْسِهِ ۖ وَمَنْ عَمِيَ فَعَلَيْهَا… ) (…So whoever will see does so for [the benefit of] his soul, and whoever is blind [does harm] against it. …): This is because, the human being will not receive except the recompense for his deeds, as Allah (swt) says:

 وَأَن لَّيْسَ لِلْإِنسَانِ إِلَّا مَا سَعَى (39) وَأَنَّ سَعْيَهُ سَوْفَ يُرَى (40) ثُمَّ يُجْزَاهُ الْجَزَاء الْأَوْفَى

(And that each person will only have what they endeavored towards, (39) and that (the outcome of) their endeavors will be seen (in their record) (An-Najm: 39-41)

(  وَمَا أَنَا عَلَيْكُم بِحَفِيظٍ… ) (…And [say], “I am not a guardian over you.”): The word (a guardian) is one of the beautiful names of Allah (swt). It means here that He will protect you from associating others in worship with Allah (swt). So, say O Muhammad: I am not a keeper over you, nor am I one to compel you:

 فَذَكِّرْ إِنَّمَا أَنتَ مُذَكِّرٌ (21) لَّسْتَ عَلَيْهِم بِمُصَيْطِرٍ (22) إِلَّا مَن تَوَلَّى وَكَفَرَ (23) فَيُعَذِّبُهُ اللَّهُ الْعَذَابَ الْأَكْبَرَ (24) إِنَّ إِلَيْنَا إِيَابَهُمْ (25) ثُمَّ إِنَّ عَلَيْنَا حِسَابَهُمْ

(So, (continue to) remind (O Prophet), for your duty is only to remind. (21) You are not (there) to compel them (to believe). (22) But whoever turns away, persisting in disbelief, (23) then Allah will inflict upon them the major punishment. (24) Surely to Us is their return, (25) then surely with Us is their reckoning.) (Al-Ghashiya: 21-26)