Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(And whoso desireth the Hereafter) i.e. Paradise by performing that which was made obligatory upon him (and striveth for it with the effort necessary) strives to enter Paradise by performing the acts that lead to it, (being a believer) and besides this he is a sincere believer; (for such, their effort) their works (findeth favour (with their Lord)) their works are accepted. This verse was revealed about Bilal the Muezzin.
And whoever desires the Hereafter and strives for it with the necessary effort, [that is] he performs the deeds worthy of it, being a believer (wa-huwa mu’minun is a circumstantial qualifier) — for such their effort will find favour, with God, that is, [their effort will be] accepted and rewarded.
And whoever desires the Hereafter, by the purity of his preparedness and the soundness of his primordial nature and has fulfilled the preconditions of what he desires in the way of having faith and performing righteous deeds, his striving shall receive gratitude in the form of the actualisation of what he desired, as has been said, 'He who seeks shall find'. For the true seeking and sincere desire can only come about upon the actualisation of the preparedness of the thing sought. When that preparedness - which is the indication that the thing sought has been actualised for him in potentiality and that there has been determined for him in the [Preserved] Tablet the [very] causes for the emergence into actuality of what is being sought and [the causes for] its projection from the Unseen to the visible, which is the striving required for that [thing] and what constitutes a duty upon him to strive for, in the way meant by His words: and strives for it with the necessary effort, that is, the striving required for it [of him] - is combined with the precondition of faith in the Unseen that enjoys certitude, then that [thing which he desires] will necessarily be actualised for him.
The Reward of Those who desire this World and Those who desire the Hereafter
Allah tells us that not everyone who desires this world and its luxuries gets what he wants. That is attained by those whom Allah wants to have it, and they get what He wills that they should get. This Ayah narrows down the general statements made in other Ayat. Allah says:
(We readily grant him what We will for whom We like. Then, afterwards, We have appointed for him Hell) meaning, in the Hereafter,
(he will burn therein) means, he will enter it until it covers him on all sides,
(disgraced) means, blamed for his bad behaviour and evil deeds, because he chose the transient over the eternal,
(rejected.) means, far away (from Allah's mercy), humiliated and put to shame.
وَمَنْ أَرَادَ الاٌّخِرَةَ
(And whoever desires the Hereafter) wanting the Hereafter and its blessings and delights,
وَسَعَى لَهَا سَعْيَهَا
(and strives for it, with the necessary effort due for it) seeking it in the right way, which is following the Messenger.
(while he is a believer,) means, his heart has faith, i.e., he believes in the reward and punishment,
فَأُولَـئِكَ كَانَ سَعْيُهُم مَّشْكُورًا
(then such are the ones whose striving shall be appreciated, (rewarded by Allah).)
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
The Arabic word Ajilah literally means something which can be had immediately, but the Qur'an employs it as a term for "This World" which yields its advantages and results in this worldly life. Its antonym is Akhirat (Hereafter) which will yield its advantages and results after death in the life of the Next World.
The person who does not believe in the life of the Hereafter deserves Hell, because he strives only for the successes and good things of this world and his endeavors are confined to material objects. Consequently, such a person becomes a mere worshiper of this world and adopts wrong conduct, for he has no sense of personal responsibility and accountability to God and ultimately deserves the torment of Hell.
"His endeavors will be appreciated": he will be rewarded for the efforts he had made for success in the Hereafter.
Allah gives the provisions of this world both to those who strive for this world and to those who strive for the Hereafter, but it is the gift of Allah alone and not of anyone else. It does not lie in the power of the worshipers of the world to deprive the seekers after the Hereafter of these provisions: nor have the seekers after the Hereafter any power to withhold these provisions from the worshipers of the world.
This is to show that the seekers after the Hereafter have been exalted over the worshipers of the world even in this worldly life. However, this exaltation is not in regard to the good things of this world -rich food and dress, palatial dwellings, limousines, helicopters and other grand things, but it is from another point of view. They enjoy that true honor, love and good-will which is denied to the tyrants and the rich people in spite of the fact that they may be indigent. This is because whatever the seekers after the Hereafter get in this world, it is earned in righteous and honest ways, while the worshipers of the world amass wealth by employing dishonest and cruel ways. Then the former spend what they get with prudence and righteousness. They fulfill the obligations they owe to others. They spend their money in the Way of Allah and to please Allah on the needy.and the indigent. In contrast to them, the worshipers of this world spend their money in.the enjoyment of luxuries, wicked works, corruption and spreading other evil things. This makes the former models of God-worship and purity in every respect and distinguishes them so clearly, from the worshipers of the world that they shine in exaltation over the latter. These things clearly indicate that in the next world the grades of the seekers after the Hereafter will be far greater and their superiority far higher than those of the worshipers of the world.