Tafsir of Al-Mu'minoon 23:115

{عَبَثًا} (In vain): This is a state (ḥāl), meaning: "as those who play," similar to His saying: {لَاعِبِينَ} (in play). Or, it is a causative object (mafʿūl lahu), meaning: We did not create you for play. Nothing compelled Us to create you except a wisdom that necessitated it, which is: that We might burden you and impose upon you the hardships of acts of obedience and the abandonment of sins, then return you from the abode of obligation to the abode of recompense, so that We may reward the doer of good and punish the evildoer.

{وَأَنَّكُمْ إِلَيْنَا لَا تُرْجَعُونَ} (And that you will not be returned to Us): This is conjoined to {أَنَّمَا خَلَقْنَاكُمْ} (that We created you). It is also permissible for it to be conjoined to {عَبَثًا} (in vain), meaning: for play, and for you to be left unreturned. It is also recited as turjaʿūn (you will be returned) with a fatḥah on the tā’.

{الْحَقُّ} (The Truth): He to whom sovereignty rightfully belongs, because everything is from Him and returns to Him. Or, the Constant One who does not cease, and whose sovereignty does not vanish.

The Throne is described as "Generous" (Karīm): Because mercy, goodness, and blessing descend from it. Or, because of its attribution to the Most Generous of the generous, just as one says: "a generous house," when its inhabitants are generous. It is also recited as al-Karīmu (in the nominative case). Similar to this is: {ذُو الْعَرْشِ الْمَجِيدُ} (The Lord of the Throne, the Glorious).

{لَا بُرْهَانَ لَهُ بِهِ} (He has no proof for it): Like His saying: {مَا لَمْ يُنَزِّلْ بِهِ سُلْطَانًا} (for which He has not sent down any authority). This is a necessary attribute, like His saying: {يَطِيرُ بِجَنَاحَيْهِ} (flying with its two wings). It is brought for emphasis, not because there could exist among the gods anything for which a proof could be established. It is also permissible for it to be an interruption (iʿtirāḍ) between the condition and the response; like your saying: "Whoever does good to Zayd—no one is more deserving of goodness than him—then God is his rewarder."

It is recited as annahu lā yufliḥu (that he will not succeed): With a fatḥah on the hamzah. Its meaning is: his reckoning is the absence of success. The original is: "his reckoning is that he himself will not succeed." The term "the disbelievers" was placed in the position of the pronoun because {مَن يَدْعُ} (whoever invokes) carries the meaning of a plural. Likewise, {حِسَابُهُ * إِنَّهُ لَا يُفْلِحُ} (his reckoning is that he will not succeed) carries the meaning of: "their reckoning is that they will not succeed."

The Surah was opened with {قَدْ أَفْلَحَ الْمُؤْمِنُونَ} (Successful are the believers), and He brought at its conclusion: {إِنَّهُ لَا يُفْلِحُ الْكَافِرُونَ} (Indeed, the disbelievers will not succeed). How vast is the difference between the opening and the conclusion!

From the Messenger of God (ﷺ): "Whoever recites Surah al-Mu’minūn, the angels will give him glad tidings of spirit and fragrance, and that which will delight his eyes at the time of the descent of the Angel of Death."

It is narrated: That the beginning of Surah Qad Aflaḥa and its end are from the treasures of the Throne. Whoever acts upon the three verses from its beginning and takes admonition from the four verses at its end, he has attained salvation and success.

From ‘Umar ibn al-Khaṭṭāb (ra): When the revelation would descend upon the Messenger of God (ﷺ), a buzzing sound like the buzzing of bees would be heard near him. We waited for a while, then he faced the qiblah, raised his hands, and said: "O God, increase us and do not decrease us, honor us and do not humiliate us, give us and do not deprive us, prefer us and do not prefer others over us, and be pleased with us and satisfy us." Then he said: "Ten verses have been revealed to me; whoever upholds them will enter Paradise." Then he recited: {قَدْ أَفْلَحَ الْمُؤْمِنُونَ} until he completed the ten.