وَلَا تَقُولَنَّ لِشَيْءٍ إِنِّي فَاعِلٌ ذَلِكَ غَدًا ﴿۲۳﴾ إِلَّا أَنْ يَشَاءَ اللَّهُ وَاذْكُرْ رَبَّكَ إِذَا نَسِيتَ وَقُلْ عَسَى أَنْ يَهْدِيَنِ رَبِّي لِأَقْرَبَ مِنْ هَذَا رَشَدًا ﴿۲۴﴾ وَلَبِثُوا فِي كَهْفِهِمْ ثَلَاثَ مِائَةٍ سِنِينَ وَازْدَادُوا تِسْعًا ﴿۲۵﴾

﴾23﴿ Wa laa taqoolanna lishai'in innee faa'ilun zaalika ghadaa
﴾24﴿ Illaaa any yashaaa'al laah; wazkur Rabbaka izaa naseeta wa qul 'asaaa any yahdiyani Rabbee li aqraba min haazaa rashadaa
﴾25﴿ Wa labisoo fee kahfihim salaasa mi'atin sineena wazdaadoo tis'aa

﴾23﴿ And do not say about anything, Indeed, I will do that tomorrow
﴾24﴿ Unless [you add], If Allah wills. And remember your Lord when you forget and say, It may be that my Lord will guide me to what is nearer than this in guidance
﴾25﴿ And they remained in their cave for three hundred years, and added nine [more, according to the lunar calendar]

[23,24] In these verses, three etiquettes are mentioned:
The first etiquette is saying “In shā’ Allāh” when speaking about any future event — (إِلَّا أَنْ يَشَاءَ اللَّهُ).
This is mentioned separately in the verse, indicating that it is prohibited to speak about future matters without saying “In shā’ Allāh.”
This also proves that the Prophet (May Allah bless him and give him peace) does not possess knowledge of the unseen.
The second etiquette is: (وَاذْكُرْ رَبَّكَ إِذَا نَسِيتَ) – “And remember your Lord when you forget.”
The commentators have mentioned several meanings of this phrase:
First meaning: Remember your Lord by saying “In shā’ Allāh” when you recall it after having forgotten. It is narrated from Ibn ‘Abbās (may Allah be pleased with them both) that even if a person remembers a year later, he should say it. Ibn Jarīr says that the Sunnah of saying “In shā’ Allāh” will still be fulfilled, even with such delay, and it does not invalidate the initial statement.
Second meaning: Remember your Lord by seeking forgiveness and praising Him when you remember that you forgot to say “In shā’ Allāh.”
Third meaning: Remember the punishment of your Lord when you abandon any of His commands.
The third etiquette is in (وَقُلْ عَسَى أَنْ يَهْدِيَنِ رَبِّي لِأَقْرَبَ مِنْ هَذَا رَشَدًا) – “And say: It may be that my Lord will guide me to something nearer than this in right conduct.”
Commentators have given three interpretations of this verse:
First meaning: It is hoped that my Lord will guide me to something more enlightening than the story of the Companions of the Cave in guiding people.
Second meaning: It is hoped that my Lord will guide me to an answer to your question that is closer in accuracy than what I have told you.
Third meaning: Since Allah did not cause you to remember what was forgotten, then say: It is hoped that my Lord will guide me to something closer and better than what was forgotten, in terms of goodness and benefit.
Some scholars have also said that this phrase is a devotional remembrance to be recited when one forgets to say “In shā’ Allāh.”
[25] Regarding this verse, there are two opinions:
The first opinion is that this statement is from Allah Most High, informing us of the actual duration the Companions of the Cave remained asleep in the cave until they woke up.
The second opinion is that this is a quotation from the People of the Book—that this is what they claimed—and based on this view, the statement is linked to (يَقُولُونَ) mentioned earlier in verse 22. So, according to this interpretation, it is a statement of the people, not from Allah.
However, the first opinion is stronger for two main reasons:
1. This phrase (وَازْدَادُوا تِسْعًا)—“and they added nine”—is not found in the scriptures of the People of the Book.
2. The phrase is too far removed from the previous (يَقُولُونَ) with a large unrelated passage in between, making such a grammatical connection weak.
This first view has been preferred by scholars such as Ibn Kathīr and Ibn Jarīr.
(ثَلَاثَ مِائَةٍ سِنِينَ) – The word سنين is either a badal (substitute) or an ‘aṭf bayān (clarifying phrase) for ثلاث مائة, but not a tamyīz (specification), because the tamyīz of مائة is singular and in the genitive case.
According to the second opinion, ثلاث مائة was stated, and someone asked, “Three hundred of what?” So it was clarified as سنين (years), with the implied word أعني (I mean) between them.
(وَازْدَادُوا تِسْعًا) – “And they added nine” – This phrase is brought separately because the three hundred refers to the solar calendar, and the nine is an addition based on the lunar calendar.
This is because every hundred solar years equals about 103 lunar years, so over 300 solar years, the difference is about nine years.
Both calendars are mentioned—solar (used by the People of the Book) and lunar (used by the unlettered Arabs)—to acknowledge and include both systems of reckoning.