The “two barriers”
In Surah Al-Kahf, Dhal-Qarnayn reaches a point between “two barriers” i.e. saddain. This word Saddain is also used in Surah Yā Sīn, the Nabī is described as being sent to a people with a “barrier before them and a barrier behind them”, basically two barriers, it is likely they are the same person that were sent to the same people.
ٱلقرءان سورة الكهف 18:93
حَتَّىٰٓ إِذَا بَلَغَ بَيْنَ ٱلسَّدَّيْنِ وَجَدَ مِن دُونِهِمَا قَوْمًا لَّا يَكَادُونَ يَفْقَهُونَ قَوْلًا
• Saheeh International
Until, when he reached [a pass] between two mountains, he found beside them a people who could hardly understand [his] speech.
Al-Kahf (18), ʾĀyah 93
ٱلقرءان سورة يس 36:9
حَتَّىٰٓ إِذَا بَلَغَ بَيْنَ ٱلسَّدَّيْنِ وَجَدَ مِن دُونِهِمَا قَوْمًا لَّا يَكَادُونَ يَفْقَهُونَ قَوْلًا
• Saheeh International
And we have put before them a barrier and behind them a barrier and covered them, so they do not see.
Yā Sīn (36), ʾĀyah 9
Word Count Parallel
In the story of Dhal-Qarnayn in Surah Al-Kahf, the word “means” which is سَبَبًا (sababa) is mentioned exactly 4 times. Similarly, the name Muḥammad is mentioned exactly 4 times across the whole Qurʾān.
18:84 – شَىْءٍ سَبَبًا
18:85 – فَأَتْبَعَ سَبَبًا
18:89 – ثُمَّ أَتْبَعَ سَبَبًا
18:92 – ثُمَّ أَتْبَعَ سَبَبًا
3:144 – وَمَا مُحَمَّدٌ إِلَّا رَسُولٌ
33:40 – مَّا كَانَ مُحَمَّدٌ أَبَآ أَحَدٍ مِّن رِّجَالِكُمْ
47:2 – وَءَامَنُوا۟ بِمَا نُزِّلَ عَلَىٰ مُحَمَّدٍ
48:29 – مُّحَمَّدٌ رَّسُولُ ٱللَّـهِ
Dhal-Qarnayn is a title which means Possessor of Two Horns/Eras. The word Qarn means a horn/realm/era, Qarnayn is the dual form of this, this title is for a person who carries immense authority or possession over two realms/eras, this parallels Muḥammad’s role the “Seal of the Prophets” i.e. Khātam An-Nabiyyīn and a “mercy to the worlds”.
Phrase Parallel
The word Kulli Shayʾin (كُلِّ شَيْءٍ) meaning “everything” is mentioned around 120 times in the Qur’an. Of these are a few mentioned for specific individuals, these are Mūsā, Dhal-Qarnayn and the Nabī. Mūsā is the example for Nabī, some people claimed that Mūsā is Dhal-Qarnayn, but that’s actually false, Dhal-Qarnayn is just similar to Mūsā because the Nabī is Dhal-Qarnayn. The rest of the mentions of “everything” in the Qur’an are generally referring to Allah’s knowledge and power, the angels carrying out His commands, what they created by His command and what they record in The Book.
16:89 – كُلِّ شَيْءٍ
18:84 – كُلِّ شَيْءٍ