As for the verbal reason, it is to preserve the harmony of the verse-endings; that is, they all end with the letter alif.
It may be asked: Allah, Glorified and Exalted, says, ﴿Indeed, upon Us rests guidance, and indeed, to Us belong the Hereafter and this worldly life.﴾ What, then, is the distinction?
The answer is that Allah Most High has undertaken to explain guidance and make it clear to creation. Sovereignty, however, belongs to Allah: the sovereignty of the Hereafter and this worldly life. Hence He says, ﴿And indeed, to Us belong the Hereafter and this worldly life.﴾ He, Mighty and Majestic, then says, ﴿So I have warned you of a blazing Fire.﴾ “I have warned you” means: I have frightened you; and “a Fire” means the Fire of the Hereafter. ﴿Blazing﴾ means burning fiercely. It has many descriptions in the Quran and sunnah.
﴿No one will burn in it except the most wretched.﴾ “No one will burn in it” means that no one will be burned by it “except the most wretched,” namely, the one for whom wretchedness has been decreed. Wretchedness is the opposite of blessedness, as Allah Most High says, ﴿As for those who are wretched, they will be in the Fire﴾ [Hūd: 106], and, ﴿As for those who are blessed, they will be in Paradise﴾ [Hūd: 108]. Thus, “the most wretched” means the one for whom blessedness was not decreed. He is the one who will burn in the blazing Fire.
He then explains this by saying, ﴿The one who denied and turned away.﴾ Denial pertains to reports, while turning away pertains to commands and prohibitions. Such a person denied the reports and refused to believe. He was told, “You will be resurrected,” but replied, “I will not be resurrected.” He was told, “There are a Paradise and a Fire,” but replied, “There are no Paradise and Fire.” He was told, “Such and such will happen,” but replied, “It will not happen.” This is denial. ﴿Turned away﴾ means that he turned away from obeying Allah and from what His messengers brought. This is the wretched person.
﴿But the most God-fearing will be kept away from it﴾ means that he will be kept away from this blazing Fire. “The most God-fearing” is an elative form derived from taqwā (fearful obedience to Allah); it means the one who fears Allah Most High as He ought to be feared. ﴿The one who gives his wealth to purify himself﴾ means that he gives his wealth to those entitled to it in such a way as to purify himself thereby. That is, he cleanses himself through it. Allah Most High says, ﴿Take charity from their wealth, by which you purify and cleanse them, and pray for them