Tafsir of Al-Isra 17:8

{ It may be that your Lord will have mercy upon you} (after the second resurrection, if you repent and desist from sins). { But if you return} (to corruption after what has preceded from you), { We will return} (to punishment, so We will punish you in this world just as We punished you the first two times). This is also among what is required for them in the Book, and likewise the following sentence. They did return by denying the Prophet (peace and blessings be upon him) and intending to kill him, so Allah the Exalted returned by empowering the Prophet (peace and blessings be upon him) over them, so he killed Banu Qurayza, exiled Banu al-Nadir, and imposed the jizya (poll tax) upon the rest. It is also said: They returned, and Allah returned by empowering the Chosroes (Persians) over them, who did to them what they did, such as imposing tribute and the like. The first is narrated from al-Hasan and Qatada. The expression "We will return" is used to indicate that it is not fitting for them to return.

{ And We have made Hell a prison for the disbelievers} (8). Ibn Abbas and others said: That is, a prison. In al-Bahr, the words of Labid are cited: "And standing [in] the ranks of those who dominate necks, as if they were jinn standing at the door of the hasir (mat/prison)." If it is a noun for the known place, it is a static noun (jamid) that does not require feminine or masculine agreement. If it is in the meaning of hasir (confining), meaning encompassing them—as fa'il in the form of fa'il—it would require agreement; thus, the lack of agreement here is either because it is on the measure of attribution, like layin (seller of dairy) and tamir (seller of dates), meaning "possessor of confinement." It is on this basis that the verse { The heaven will break apart by it} is explained—meaning possessor of breaking—or it is taken as fa'il in the meaning of maf'ul (passive). It is said that the masculine form is due to interpreting Jahannam (Hell) as masculine, and it is said because its feminine gender is not real; Abu al-Baqa' reported this, though it is as you see.

Ibn al-Mundhir and others narrated from al-Hasan that he explained it as a mattress and a bed. Al-Raghib said: It is as if the woven mat is intended, and this term is applied to it because some of its strands confine others; thus, hasir in this sense means "confined," and the speech contains eloquent simile. Hasir has also come to mean "authority/ruler." Al-Raghib cited the aforementioned poem as evidence for this, then said: "Naming it so is either because he is confined, like one who is veiled, or because he is hasir (confining), meaning preventing whoever wishes to prevent him from reaching him." End quote. To apply what is in the verse to that is something not addressed, and applying it is extremely far-fetched, so it should not be applied to it, even if it contains a subtle meaning perceived through reflection.

The outward sense would have been to say "for you" instead of "for the disbelievers," but He turned away from that to register their disbelief upon their return, to condemn them for that, and to notify the cause of the judgment.