Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(The life of the world) that which is in the life of the world (is but a sport) vain sport (and a pastime) and exultation which does not last. (And if ye believe) and if you are steadfast in your faith in Allah and His Messenger (and ward off (evil)) disbelief, idolatry and indecencies, (He will give you your wages) He will give you the reward of your works, (and will not ask of you your worldly wealth) all your worldly wealth to give to charity.
The life of this world, that is to say, preoccupation [solely] with it, is merely play and diversion; but if you believe and are wary, of God, [both of] which pertain to [the goal of] the Hereafter, He will give you your rewards, and will not ask you your wealth [in return], all of it, rather, only the alms that are required from it.
(And if you believe and have Taqwa of Allah, He will grant you your rewards, and will not ask from you (to sacrifice all of) your possessions.) meaning, He is in no need of you, and asks you for nothing. He only ordained giving charity from your wealth so that you would help your needy brothers. The benefit of that would then come back to you, as well as the rewards. Allah then says,
ؤإِن يَسْـَلْكُمُوهَا فَيُحْفِكُمْ تَبْخَلُواْ
(If He would demand of you all of it and urge you, you would withhold.) meaning, if He pressures you much, you would become stingy.
(And He will expose your (secret) ill--wills.) Qatadah said, "Allah knows that extracting wealth (i.e., money from people) brings about ill-wills. '' Indeed, Qatadah has said the truth, because money is dear to the people, and they do not spend it except in things that are dearer to them than it. Allah then says,
(Here you are now invited to spend in Allah's cause; but among you are those who withhold (stingily).) meaning, they refuse to spend. Allah continues,
يَبْخَلُ وَمَن يَبْخَلْ فَإِنَّمَا يَبْخَلُ عَن
(And whoever acts stingily is but stingy toward himself.) meaning, he only reduces his own rewards, and the bad outcome of that will come back to him.
(For Allah is indeed Al-Ghani) Allah is in need of nothing else, whereas everything is ever in need of Him. Thus, Allah says,
(while you are the needy.) meaning, specifically of Him. The description of Allah as Al-Ghani (in no need) is a necessary description of Allah; on the other hand, the description of the creation as Faqr (needy) is a necessary description for them that they cannot avoid. Allah then says,
(And if you turn away, ) which means, if you turn away from obeying Him and adhering to His Laws.
(He will replace you with other people; then they will not be like you.) meaning, rather, they will be people who will listen to Him and obey His commands. This concludes the Tafsir of Surat Al-Qital. And Allah is worthy of all praise and gratitude.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
This sentence has two meanings:
(1) That Allah will render vain and fruitless all those works which they had performed as "good works", and they will get no reward whatever for them in the Hereafter; and
(2) that all the devices that they are adopting to obstruct the way of Allah and His Messenger's Religion will prove ineffective and fruitless.
In other words, the deeds' being beneficial and yielding of good results depends wholly on one's obedience to Allah and His Messenger. After one has turned away from obedience, no deed remains a good deed so that one may deserve any reward for it.
Here, one should bear in mind the fact that when this discourse was revealed only a handful of the Muslims consisting of a couple of hundreds of the Muhajirin and Ansar living in the small town of Madinah were upholding the standard of Islam and they were not only faced by the powerful Quraish but also by the whole of pagan Arabia. Such were the conditions when they were exhorted 'not to be faint-hearted and not to beg (the enemy) for peace", but to make preparations for the decisive conflict. This does not mean that the Muslims should never negotiate for peace, but it means that in a state like this it is not right to initiate peace negotiations when it shows the Muslims' weakness, for it will still further embolden the enemy. The Muslims should first establish their superiority in power and strength; then if they negotiate peace there will be no harm.
That is, "As against the Hereafter, this world is no more than a means of temporary entertainment. The success or failure here is not anything real and enduring, which might in any way be important. The real life is life hereafter success in which should be man's main concern. (For further explanation, see E.N. 102 of Surah AI-`Ankabut).
That is, "Allah is Self-Sufficient: He does not need taking anything from you for His own Self. If He tells you to expend something in His way, He does so not for Himself but only for your own good."
That is, "He does not put you to any severe trial that may bring out your weaknesses. "