Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(Those are they whose works) good deeds (have failed) made void (in the world and the Hereafter) that is, they will not be given reward for them in the Hereafter; (and they have no helpers) who will save them from Allah's punishment.
Those are the ones whose works, what good they did in the way of charity and kindness to kin, have failed, [whose works] are invalid, in this world and the Hereafter, and so they have nothing to reckon with, since these [works] are of no consequence; they have no helpers, [no] protectors from the chastisement.
Those are the ones whose works have failed, those [works] which they performed while following the religion of their prophets and that is because while they were following blindly their prophet they were still saved by virtue of their following [him], since their prophets were their intercessors mediating between them and God in order to procure for them the [divine] effusion; but when they denied the prophets and their just followers they were contravening their particular prophet, since all prophets follow one creed in reality, namely, the belief in the Oneness [of God], without distinguishing between them, being as they are [all] upon the one [single] truth. Thus he who contravenes one [prophet] has in effect contravened all. Likewise, he who contravenes the upholders of justice from among the followers of the prophets is himself unjust and he who is unjust has, by virtue of his injustice, abandoned the following [of prophets]; similarly the denier of the followers is a denier of those who are followed, and the denier of the shadow [of God's Oneness] is a denier of the Essence, abandoning Its light. Once they have contravened their prophet there no longer exists any contact or correspondence between them and him that enables [the procurement of] effusion from His light and they are thus veiled from His light. Although their works had been illumined by His light by virtue of their following [the prophet], not because of any essential light that these [works] possess, since they are not produced out of certainty, once they are veiled from their prophet the accidental light [of these works] disappears and they become dark and like all other evil deeds from among the attributes of the commanding soul. Here [the following comes to mind], something which I have heard on more than one occasion: the slaying of the disbelievers of the faculties of the commanding soul at the hands of the prophets of the hearts and the justice-commanding spiritual faculties.
Chastising the Jews for Their Disbelief and for Killing the Prophets and Righteous People
This Ayah chastises the People of the Book for the transgression and prohibitions they committed by their denials in the past and more recent times, of Allah's Ayat and the Messengers. They did this due to their defiance and rejection of the Messengers, denial of the truth and refusal to follow it. They also killed many Prophets when they conveyed to them what Allah legislated for them, without cause or criminal behavior committed by these Prophets, for they only called them to the truth,
(And kill those men who order just dealings) thus, demonstrating the worst type of arrogance. Indeed, the Prophet said,
«الْكِبْرُ بَطَرُ الْحَقِّ وَغَمْطُ النَّاس»
(Kibr (arrogance) is refusing the truth and degrading people)
This is why when they rejected the truth and acted arrogantly towards the creation, Allah punished them with humiliation and disgrace in this life, and humiliating torment in the Hereafter. Allah said,
فَبَشِّرْهُمْ بِعَذَابٍ أَلِيمٍ
(then announce to them a painful torment) meaning, painful and humiliating,
(They are those whose works will be lost in this world and in the Hereafter, and they will have no helpers. ).
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
This is an ironical way of bringing home to the disbelievers the consequences of those mischievous deeds in which they rejoice today, regarding them as "nice things."
That is, "As they have spent all their energies and powers in evil ways, their works will bring them to ruin both in this world and in the Next World"
That is, "There is no such power which can bring out good results from their wrongly directed efforts or at least make them harmless. All the various agencies, which they believe will help them in this world or in the Next World or in both, shall be absolutely of no avail to them anywhere."
Those are the ones whose works have failed in this world and the hereafter; they have no helpers. Those are the ones for whom no success is granted in their works tawfīq bi-aʿmāl today nor realization of their hopes taḥqīq li-āmāl tomorrow. That is only because they have lost Our help in both abodes and did not bear witness to Our might and power.