أَلَمْ يَعْلَمُوا أَنَّهُ مَنْ يُحَادِدِ اللَّهَ وَرَسُولَهُ فَأَنَّ لَهُ نَارَ جَهَنَّمَ خَالِدًا فِيهَا ذَلِكَ الْخِزْيُ الْعَظِيمُ ﴿۶۳﴾ يَحْذَرُ الْمُنَافِقُونَ أَنْ تُنَزَّلَ عَلَيْهِمْ سُورَةٌ تُنَبِّئُهُمْ بِمَا فِي قُلُوبِهِمْ قُلِ اسْتَهْزِئُوا إِنَّ اللَّهَ مُخْرِجٌ مَا تَحْذَرُونَ ﴿۶۴﴾ وَلَئِنْ سَأَلْتَهُمْ لَيَقُولُنَّ إِنَّمَا كُنَّا نَخُوضُ وَنَلْعَبُ قُلْ أَبِاللَّهِ وَآيَاتِهِ وَرَسُولِهِ كُنْتُمْ تَسْتَهْزِئُونَ ﴿۶۵﴾

﴾63﴿ Alam ya'lamooo annahoo mai yuhaadidillaaha wa Rasoolahoo fa'anna lahoo Naara jahannama khaalidan feehaa; zaalikal khizyul 'Azeem
﴾64﴿ Yahzarul munaafiqoona an tunaz zala 'alaihim Sooratun tunabbi 'uhum bimaa feequloobihim; qulistahzi'oo innal laaha mukhrijum maa tahzaroon
﴾65﴿ Wala'in sa altahum layaqoolunna innamaa kunnaa nakhoodu wa nal'ab; qul abillaahi wa 'Aayaatihee wa Rasoolihee kuntum tastahzi'oon

﴾63﴿ Do they not know that whoever opposes the limits set by Allah and His Messenger, for him is the Fire of Hell, wherein he will remain forever? That is the great disgrace.
﴾64﴿ The hypocrites fear that a surah will be revealed about them, informing the believers of what is in their hearts. Say, "Mock as you wish; indeed, Allah will expose that which you fear being exposed."
﴾65﴿ If you ask them (about what they said), they will surely say, “We were only talking idly and joking.” Say, “Was it Allah, His verses, and His Messenger that you were mocking”

[63] This verse contains a warning of the Hereafter and mentions one of the hypocrites' disgraceful traits.
(يُحَادِدِ) – means opposing the boundaries set by Allah the Exalted and His Messenger (May Allah bless him and give him peace), by creating limits of their own.
There are two types of limits (hudood):
1. Legal punishments for certain sins, such as the punishment for adultery, theft, etc.
2. The prescribed way (sunnah) in every legal ruling – this is also considered a limit.
From this perspective, every innovation (bid'ah) is opposition to Allah and His Messenger.
A similar warning is found in verses (5) and (20) of Surah Al-Mujadilah.
[64] This verse is also a warning, and it mentions one of their disgraceful traits.
The meaning of the verse is that they used to mock the Prophet and the Qur'an, but then they feared that Allah the Exalted might reveal a surah exposing their evil, informing the believers of their true condition.
However, Allah the Exalted did reveal this surah exposing their faults—because of that, this surah is also called Surah Al-Fadhihah (the “Exposer” or “Disgracer”).
(قُلِ اسْتَهْزِئُوا) – this shows that they used to mock Allah, His Messenger, and the believers. This command is not literal, but a threat and a warning.
[65] This verse mentions two of their disgraceful traits: (نَخُوضُ وَنَلْعَبُ) – “we were engaging in idle talk and play.”
This was their excuse for mocking, but it reflects the famous saying: “The excuse is worse than the sin.”
Because indulging in idle and playful talk about Allah the Exalted, His Messenger, and His verses is a major sin.
Al-Jassas and Fakhr al-Razi wrote that even jokingly uttering words of disbelief (kufr) is itself kufr.
نَخُوضُ – refers to engaging in inappropriate or false talk, especially gossip and useless discussions.
نَلْعَبُ – means doing or saying something inappropriate just for passing time, even if that wasn't the intention.
(تَسْتَهْزِئُونَ) – this proves that idle talk and play are equivalent to mockery, and mockery of Allah the Exalted includes mocking His names, His attributes, or His rulings.