Note: The entire section of Surah Al Hashr from verses 18-24 is cautions to warn men and cautiones them that there is still time to review what they have sent forward and seek forgiveness of Allah lest the angel of death knocks at their door and there is no time to repent. Please read the exegesis / tafsir of
يٰۤاَيُّهَا الَّذِيۡنَ اٰمَنُوۡا اتَّقُوا اللّٰهَ وَلۡتَـنۡظُرۡ نَـفۡسٌ مَّا قَدَّمَتۡ لِغَدٍ ۚ وَاتَّقُوا اللّٰهَؕ اِنَّ اللّٰهَ خَبِيۡرٌۢ بِمَا تَعۡمَلُوۡنَ
(18) O you who have believed, fear Allah. And let every soul look to what it has put forth for tomorrow - and fear Allah. Indeed, Allah is Acquainted with what you do.
It is a rule of the Qur'an that whenever the hypocritical Muslims are taken to task for their hypocrisy, they are given admonition also so that whoever of them has some life left in his conscience, may feel remorse for his conduct and attitude and may make an effort, out of the fear of Allah, to come out of the pit into which his worship of the self has thrown him.
" Fear Allah and let every person look to what he sends forward for the morrow " "For the morrow": for the Hereafter. That is, this whole worldly life is "today", whose "tomorrow" is the Day of Resurrection, which is going to follow it. Adopting this style Allah has, in a wise manner, made man understand the truth that just as that person is highly foolish, who gambles away his all for the enjoyment of today and does not realize whether tomorrow he would be left with anything to eat and a place of shelter or not, so is that person also only working for his own doom, who is too absorbed in making; his world to pay heed to the Hereafter, whereas the Hereafter is to follow this world just as today is to be followed by tomorrow, and there he would find nothing if he has sent nothing ahead for the morrow. Besides, the other wise point here is that every person has been appointed his own censor. Unless a person develops in himself the sense of what is good for him and what is evil, he cannot appreciate whether what he is doing will make his future in the Hereafter or mar it. And when this sense becomes active in himself, he will have to calculate and see for himself whether the way in which he is expending his time, his wealth, his energies and capabilities leads to Heaven or Hell. To do so is in his own interest; for if he does not do so he will ruin his own future itself.
Yusuf Ali Explanation: The "fear of Allah" is akin to love; for it means the fear of offending Him or doing anything wrong that will forfeit His Good Pleasure. This is Taqwa, which implies self-restraint, guarding ourselves from all sin, wrong, and injustice, and the positive doing of good. See ii. 2:
(ii:2) This is the Book; in it is guidance sure without doubt to those who fear Allah.
Taqwa and the verbs and nouns connected with the root, signify: (1) the fear of God which according to the writer of Proverbs (i.7) in the Old Testament is the beginning of Wisdom; (2) restraint, or guarding one's tongue, hand, and heart from evil; (3) hence righteousness, piety good conduct. All these ideas are implied; in the translation, only one or other of these ideas can be indicated according to the context. See also xivii 17; and ixxiv 56.
The positive side of Taqwa, or "fear of Allah" (see last note) is here emphasized. It is not merely a feeling or an emotion: it is an act, a doing of things which become a preparation and provision for the Hereafter, - the next life, which may be described as "the morrow" in relation to the present Life, which is "to-day". A) The repetition emphasizes both sides of Taqwa: "let your soul fear to do wrong and let it do every act of righteousness; for Allah observes both your inner motives and your acts, and in His scheme of things everything will have its due consequences."
Javed Ahmad Ghamidi Explanation: This refers to what he has done for the Day of Judgement. It is referred to by the word “tomorrow.” The purpose is to direct attention to its proximity as well as to its certainty.
The words اِتَّقُوا اللّٰہَ (fear God) are repeated so that the importance of the matter is driven in the minds of the addressees.
Having asked man to fear Allah and take a look at one's past which has been already recorded, there comes another caution in the next verse, the number 19, which tells man the fate ofthose who did not fear Allah and were forgotten by Allah:
وَلَا تَكُوۡنُوۡا كَالَّذِيۡنَ نَسُوا اللّٰهَ فَاَنۡسٰٮهُمۡ اَنۡفُسَهُمۡؕ اُولٰٓـئِكَ هُمُ الۡفٰسِقُوۡنَ
(19) And be not like those who forgot Allah, so He made them forget themselves. Those are definitely disobedient.
That is, forgetfulness of God inevitably leads to forgetfulness of one's own self. When man forgets that he is slave to the Almighty, he will inevitably form a wrong view of his position in the world, and his whole life will go wrong because of this basic error. Likewise, when he forgets that he is slave to nobody except Allah, he does not serve the one whose slave actually he is not. This also is a grave and all-pervading misunderstanding, which corrupts his whole life. Man's real position in the world is that of a slave; he is not free and self-sufficient; and he is slave of only One God, and is no one else's slave beside Him. The person who, in not know this truth, does not in fact know himself. And the person who in spite of knowing this, forgets it at any moment, may commit an act at that very moment, which a disbeliever, or a polytheist or a man forgetful of God only would commit. Man's remaining firm and steadfast on the right path entirely depends on his remembering God at all times. For as soon as he, becomes heedless of Him. he becomes heedless of himself and this very heedlessness turns him into sinfulness.
Javed Ahmad Ghamidi Explanation: This is a reference to the Jews from whom the Hypocrites received guidance and with whom they would connive to oppose Islam and the Muslims. The words فَاَنۡسٰہُمۡ اَنۡفُسَہُمۡ used for them point to a very important reality.
Imam Amin Ahsan Islahi has explained it thus: … Those who forget God become indifferent to their own good and evil and to their fate. All value, significance and majesty of life depends on understanding the reality that the Almighty has not given it to us to indulge in a few days of luxury; He has given it to us so that we spend it in obedience to Him and earn the eternal kingdom of heaven. This pinnacle can of course be achieved by someone who always keeps in mind that he has not been given life by chance; on the contrary, it is a blessing of a Gracious being and He has given it with a special purpose. If a person leads his life in accordance with this special purpose, it will be a great eternal reward for him, and if he forgets this, it will automatically become an eternal curse for him.(Amin Ahsan Islahi, Tadabbur-i Qur’an, vol. 8, 308)