َ وَلَا تَكُونُوا كَالَّذِينَ نَسُوا اللَّهَ فَأَنْسَاهُمْ أَنْفُسَهُمْ أُولَئِكَ هُمُ الْفَاسِقُونَ ﴿۱۹﴾ لَا يَسْتَوِي أَصْحَابُ النَّارِ وَأَصْحَابُ الْجَنَّةِ أَصْحَابُ الْجَنَّةِ هُمُ الْفَائِزُونَ ﴿۲۰﴾ لَوْ أَنْزَلْنَا هَذَا الْقُرْآنَ عَلَى جَبَلٍ لَرَأَيْتَهُ خَاشِعًا مُتَصَدِّعًا مِنْ خَشْيَةِ اللَّهِ وَتِلْكَ الْأَمْثَالُ نَضْرِبُهَا لِلنَّاسِ لَعَلَّهُمْ يَتَفَكَّرُونَ ﴿۲۱﴾

﴾19﴿ Wa laa takoonoo kallazeena nasul laaha fa ansaahum anfusahum; ulaaa'ika humul faasiqoon
﴾20﴿ Laa yastaweee as-haabun naari wa ashaabul jannah; as haabul jannati humul faaa'izoon
﴾21﴿ Law anzalnaa haazal quraana 'alaa jabilil lara aytahoo khaashi'am muta saddi'am min khashiyatil laah; wa tilkal amsaalu nadribuhaa linnaasi la'allahum yatafakkaroon

﴾19﴿ And do not be like those who forgot Allah, so He made them forget their own souls. They are the true defiantly disobedient ones
﴾20﴿ The inhabitants of the Fire and the inhabitants of Paradise are not equal. The inhabitants of Paradise are the ones who will attain success
﴾21﴿ Had We sent down this Qur'an upon a mountain, you would have seen it humbled and torn apart out of the fear of Allah. And these are the examples We present to the people so that they may reflect

[19] This is the fourth address — it instructs believers to avoid all forms of resemblance to disbelievers, hypocrites, and polytheists.
This prohibition includes similarity in belief, actions, character, appearance, behavior, emotions (such as grief and joy), clothing, and other aspects — all forms of imitation are forbidden.
“So He made them forget themselves” — this is a punishment matching their actions. Because of their neglect and opposition, Allah does not grant them the ability (tawfīq) to perform righteous deeds. And even if they perform some good deeds, they are mixed with shirk, innovation (bid‘ah), or showing off (riyā’), so such actions bring no benefit to their souls on the Day of Judgment.
[20] This verse provides the reason for the previous command — that believers should avoid resembling disbelievers because their end result is entirely different.
“Al-Fā’izūn” (the successful) is used here in contrast to al-Khāsirūn (the losers).
Thus, it becomes clear that in the previous verse, where fisq (rebellion) was mentioned, it leads to khusrān (loss), though the word khusrān was not explicitly used — instead, its opposite, fawz (success), is mentioned here to imply the contrast.
[21] This verse has three interpretations: First interpretation: It emphasizes the greatness of the Qur’an, along with a warning to its rejecters. The meaning is: if a mountain were given intellect and understanding like a human, and made responsible for the Qur’an, and it heard the Qur’an, it would be crushed and shattered out of humility and fear — even though it is made of dense, hard stone. Yet the rejecter’s heart is so hard that the Qur’an has no effect on it. Second interpretation: It refers to the weight and burden of the Qur’an and highlights Allah’s favor upon the Prophet (May Allah bless him and give him peace). The burden and heaviness of the Qur’an is such that mountains could not bear it, yet Allah gave His Prophet the strength to carry both the weight of its revelation and the responsibility of delivering its message. Third interpretation: It addresses the weight of the Qur’an and answers a question posed by the polytheists and Jews: why was the Qur’an not revealed all at once to the Prophet (May Allah bless him and give him peace)? The essence of the reply is that even if it were to descend all at once upon a mountain, it would not be able to bear it due to its overwhelming power — and a mountain is physically far stronger than a human being. So how could the Prophet (May Allah bless him and give him peace) bear it, except through divine support? Connection to the previous verses: The disbelievers, Jews, hypocrites, and others from the people of the Fire still have a chance to be saved — if they reflect upon the Qur’an and believe in it. Through the Qur’an, they can develop humility and fear of Allah.