that in distinction to the gardens of the hearing and heart, which are continuously renewed, the gardens of the eyes, from which they gather up evidences, are fixed and constant.
By ascribing the sealing up of the heart to Allah (May He be exalted!) and not the veiling of the eyes, it suggests that the sealing up is punishment for what they have earned, while the veiling is of their own doing.
It is also a sign that initially in respect of the heart and hearing there is choice, while in respect of the sight there is compulsion; that is, there is choice only to the extent of shutting one’s eyes.
The term “veil (ghishāwatun)” indicates that the eyes look in only one direction. And the use of the indefinite is to show this; that is, the cause of blindness is not known that it might be avoided.
The precedence of “and on their eyes (wa ‘alā abṣārihim)” is to direct attention to their eyes, for the eyes mirror the secrets of the heart.
“Great is the penalty they incur (wa la-hum ‘adhābun ‘aẓīm):” know that just as the verse alludes with this phrase to the bitter fruits in this world of the accursed tree of unbelief; so it indicates the bitter fruit of that side of it that extends to the hereafter, which is the Zaqqum-tree of Hell.
Also, the style here requires such phraseology as ‘theirs will be a terrible chastisement’ (wa ‘alayhim ‘iqābun shadīd). For in substituting words fitting for bounties, that is, “la-hum” for ‘alayhim, and “‘adhābun” for ‘iqābun, and “‘aẓīm” for shadīd is a sign that it is a sort of insinuating, condemnatory mockery as though [the Qur’an] is saying: “Their benefit, their delight, their supreme bounty will be nothing but torment.” This resembles the saying: “Greetings between them will be a painful blow,” and the verse “announce to them (lit. the glad tidings of – fa-bashshirhim) a grievous penalty.”(3:21) For the “la-” of “la-hum – (lit.) to them” denotes the consequences of the action and its benefits, as though it is reading out to them [mockingly]: “Receive the wages for what you have done!”
In the word “penalty (‘adhābun)” [the root of which also bears meanings of sweet, pleasant, etc.] is an obscure allusion reminding them that they sought pleasure and delight in this world through sinful acts, as though announcing to them: “Now taste the bitter [fruits] of your sweet life!”
And in the word “great (‘aẓīm)” is a hidden sign reminding them of the state of [the people of] Paradise who receive stupendous bounties, as though it is whispering to them: “See the vast bounties you have forfeited and how you have fallen into grievous suffering. “Great (‘aẓīm)” also strengthens the tanwīn (indefiniteness) of “penalty (‘adhābun).”