Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(O ye who believe!) the address is to the Companions of Muhammad (pbuh) (What aileth you that when it is said unto you: Go forth) with your Prophet (in the way of Allah) in obedience of Allah at the Battle of Tabuk, (ye are bowed down to the ground with heaviness) you wish to remain bowed down to the ground. (Take ye pleasure in the life of the world) i.e. in that which is in the life of this world (rather than in the Hereafter? The comfort of the life of the world is but little in the Hereafter) and will not last.
When the Prophet (s) summoned men for the Tabūk campaign, and they thought it too burdensome, because of the hardship and the extreme heat from which they were suffering, the following was revealed: O you who believe, what is wrong with you that, when it is said to you, ‘Go forth in the way of God,’ you sink down heavily (iththāqaltum: the original tā’ [of tathāqaltum] has been assimilated with the thā’, and the conjunctive hamza has been supplied), in other words, you hesitate and are disinclined to [participate in] the struggle, to the ground, to stay sitting upon it? (the interrogative is meant as a rebuke). Are you so content with the life of this world, and its delights, rather than with the Hereafter?, that is, in place of its bliss? Yet the enjoyment of the life of this world is, in, comparison with the enjoyment of, the Hereafter but little, trivial.
(Are you pleased with the life of this world rather than the Hereafter), why do you do this, is it because you prefer this life instead of the Hereafter Allah next diminishes the eagerness for this worldly life and increases it for the Hereafter,
(The life of this world, compared to the Hereafter, is just like when one of you dips his finger in the sea, let him contemplate how much of it his finger would carry.) The Prophet pointed with his index finger. Muslim collected this Hadith. Ath-Thawri narrated that Al-A`mash said about the Ayah,
(But little is the enjoyment of the life of this world compared to the Hereafter.) "What compares to the provision a traveler takes.'' `Abdul-`Aziz bin Abi Hazim narrated that his father said, "When `Abdul-`Aziz bin Marwan was dying he said, `Bring the shroud I will be covered with so that I inspect it.' When it was placed before him, he looked at it and said, `Is this what I will end up with from this life' He then turned his back and cried, while saying, `Woe to you, O life! Your abundance is truly little, your little is short lived, we were deceived by you.''' Allah warns those who do not join Jihad,
إِلاَّ تَنفِرُواْ يُعَذِّبْكُمْ عَذَابًا أَلِيمًا
(If you march not forth, He will punish you with a painful torment) Ibn `Abbas said, "Allah's Messenger called some Arabs to mobilize, but they lagged behind and Allah witheld rain from coming down on them, and this was their torment.'' Allah said,
وَيَسْتَبْدِلْ قَوْمًا غَيْرَكُمْ
(and will replace you by another people), who will give aid to His Prophet and establish his religion. Allah said in another Ayah,
(And if you turn away (from the obedience to Allah), He will exchange you for some other people and they will not be your likes.) 47:38
وَلاَ تَضُرُّوهُ شَيْئًا
(and you cannot harm Him at all), you can never harm Allah when you lag behind and stay away from joining Jihad,
وَاللَّهُ عَلَى كُلِّ شَيْءٍ قَدِيرٌ
(and Allah is able to do all things.) He is able to destroy the enemies without your help.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
From here begins the discourse (vv. 38-72) which was sent down at the time when the Holy Prophet was engaged in making preparations for the Campaign to Tabuk.
".... you should know that the goods... Hereafter" may imply two meanings. First: "When you will find that the life in the Hereafter is eternal and see that the good things and the provisions of enjoyment are countless, you will realize that the potential and the actual enjoyments of the temporary life of this world were nothing as compared with the blessings of that great Kingdom. At that time you will regret why you deprived yourselves of this everlasting happiness and bliss for the sake of the little-very little-sort-lived enjoyments of the mortal life of this world. " Second: "The goods of this worldly life are of no value in the Hereafter, howsoever abundant they might be. You shall have to give up each and everything as soon as you breathe your last, for nothing of this world can go with you to the Next World. Of course, you will get credit for what you sacrificed for the pleasure and love of Allah, and love of Islam."
A general rule of the Islamic conduct has been derived from "If you.... chastisement. " When the Muslims are commanded to go to Jihad by a public proclamation from their leader, it becomes an obligatory duty for those who are called upon to do Jihad, whether they belong to any particular group or region. So much so that the Faith of those who do not go for Jihad without a genuine excuse becomes doubtful. But even in cases where the Muslims are called upon to go forth for Jihad and there is no command for the compulsory enrollment of every able-bodied Muslim of a particular group or region, it is a religious duty (though not obligatory), and it shall be considered to have been performed even if only some Muslims go forth for it.
That is, "Allah's work does not depend on you and will be accomplished only if you do it. It is Allah's grace and bounty that He is affording you the golden opportunity of serving the cause of His Way. Therefore if you miss this opportunity because of any foolish assumption, Allah will raise another people and bestow on them the opportunity and capability of doing His work, and you will be losers".
This refers to the occasion when the disbelievers had decided to assassinate the Holy Prophet, and the very night fixed for his assassination he had left Makkah for Al-Madinah. By that time most of the Muslims had migrated to Al-Madinah in twos and threes and only a few helpless ones had remained behind in Makkah. As he was sure that he would be pursued, he took only Hadrat Abu Bakr with him and went southward instead of following the northern route to Al-Madinah and remained hidden in the Thaur Cave for three days. In the meantime the blood thirsty enemies had begun to make a thorough search for him all around Makkah and some of them reached the very mouth of the Cave where he was hidden. On this critical occasion Hadrat Abu Bakr naturally felt alarmed lest they should peep into the Cave, and see them. But the Holy Prophet remained as calm as before and reassured his Companion, saying, "Be not distressed: indeed Allah is with us."
The words ".... whether you are light or heavy..." have a very comprehensive meaning: "When it is enjoined to march forth for Jihad, you must go forth anyhow, whether you like it or not: whether you are in a state of prosperity or indigence: whether you are well-equipped or ill-equipped: whether the circumstances are favorable or adverse: whether you are young and healthy or old and weak. "
(O ye who believe! What aileth you that when it is said unto you: Go forth in the way of Allah…) [9:38]. This verse was revealed to prompt the believers to take part in the Battle of Tabuk. When the Messenger of Allah, Allah bless him and give him peace, returned from al-Ta'if and the Battle of Hunayn, he gave orders to attack the Byzantines. This happened at a time when people were living in straitened circumstances, the land was suffering from drought; it was very hot and it was time to reap the dates which were by then ripe. People found it very hard to conquer the Byzantines; they preferred to stay at home and enjoy the shade. The idea of going out to fight was very hard to accept. When Allah knew people's slackness, He revealed this verse.