َ فَبِأَيِّ آلَاءِ رَبِّكُمَا تُكَذِّبَانِ ﴿۱۸﴾ مَرَجَ الْبَحْرَيْنِ يَلْتَقِيَانِ ﴿۱۹﴾ بَيْنَهُمَا بَرْزَخٌ لَا يَبْغِيَانِ ﴿۲۰﴾ فَبِأَيِّ آلَاءِ رَبِّكُمَا تُكَذِّبَانِ ﴿۲۱﴾ يَخْرُجُ مِنْهُمَا اللُّؤْلُؤُ وَالْمَرْجَانُ ﴿۲۲﴾ فَبِأَيِّ آلَاءِ رَبِّكُمَا تُكَذِّبَانِ ﴿۲۳﴾ وَلَهُ الْجَوَارِ الْمُنْشَآتُ فِي الْبَحْرِ كَالْأَعْلَامِ ﴿۲۴﴾ فَبِأَيِّ آلَاءِ رَبِّكُمَا تُكَذِّبَانِ ﴿۲۵﴾ كُلُّ مَنْ عَلَيْهَا فَانٍ ﴿۲۶﴾

﴾18﴿ Fabi ayyi aalaaa'i Rabbikumaa tukazzibaan
﴾19﴿ Marajal bahrayni yalta qiyaan
﴾20﴿ Bainahumaa barzakhul laa yabghiyaan
﴾21﴿ Fabi ayyi aalaaa'i Rabbikumaa tukazzibaan
﴾22﴿ Yakhruju minhumal lu 'lu u wal marjaan
﴾23﴿ Fabi ayyi aalaaa'i Rabbikumaa tukazzibaan
﴾24﴿ Wa lahul jawaaril mun sha'aatu fil bahri kal a'laam
﴾25﴿ Fabi ayyi aalaaa'i Rabbikumaa tukazzibaan
﴾26﴿ Kullu man 'alaihaa faan

﴾18﴿ So which of the favors of your Lord will you both deny
﴾19﴿ He has let loose the two seas, flowing together
﴾20﴿ Between them is a barrier that they do not transgress
﴾21﴿ So which of the favors of your Lord will you both deny
﴾22﴿ From both of them come forth pearls, both large and small
﴾23﴿ So which of the favors of your Lord will you both deny
﴾24﴿ And to Allah alone belong the sailing ships, raised high in the sea like mountains
﴾25﴿ So which of the favors of your Lord will you both deny
﴾26﴿ Everything on the face of the earth will perish

[19,20] After mentioning the blessings of the land, the blessings of the sea are mentioned:
"Al-Baḥrayn" (الْبَحْرَيْنِ) refers to the two bodies of water — the fresh water that descends from the sky, forming rivers and streams upon the earth, and the saltwater seas.
Often, these two types of water meet and flow together, eventually leading to the salty oceans.
Despite flowing together, there is a barrier between them — from the very beginning, a divine, unseen partition established by the power of Allah.
"Lā yabghiyān" (لَا يَبْغِيَانِ) — meaning they cannot transgress against each other; one does not overcome or corrupt the other, so that the benefits intended from both are not lost or ruined.
[21] In the previous Ālā’ (blessings), five blessings were mentioned:
1. The creation of Adam (peace be upon him) and the human species from ṣalṣāl (sounding clay).
2. The creation of Jān and the jinn from mārij (a smokeless flame).
3. The two sunrises and sunsets (al-mashriqayn wal-maghribayn) — referring to the variety in times and directions.
4. The two seas — sweet and salty — flowing together.
5. The barrier between these two waters, preventing them from mixing and harming their individual benefits.
[22,23] In this verse, two blessings are mentioned, and among the benefits of the seas, this particular benefit is mentioned separately because the benefits of pearls and coral are also distinct from general benefits.
The scholars who specialize in gemstones are familiar with most of these benefits, and from them, medicines and compounds are also made for the treatment of diseases.
The word (مِنْهُمَا), this dual pronoun, refers to the two bodies of water themselves, meaning that these pearls and corals indeed originate from the mixing of the two waters. An example of this is like male and female.
Ibn Jarir has said that rainwater falls into the open shells in the sea, and then the shells close, and pearls are formed inside them—one or more. Some people have even observed this process.
[24,25] Among the blessings of the sea, another great blessing is mentioned: (الْمُنْشَآتُ)—meaning their sides are as tall as mountains.
This refers to large sea vessels, and it is one of the miracles of the Qur'an because such massive ships appeared in later times, yet the Qur'an had already mentioned them beforehand.
[26,27,28] In this part, another type of blessings is mentioned, and they are five: the perishing of all things, permanence, the Face of the Lord, majesty, and generosity.
And in the second verse, five attributes of Allah the Exalted are mentioned.
(كُلُّ مَنْ عَلَيْهَا)—"everyone upon it" refers to jinn and humans, because they are the ones being addressed in this surah.
(وَجْهُ رَبِّكَ)—Qurtubi has narrated from Ibn Abbas (may Allah be pleased with them both) that what is meant by "Face" is the Essence and Existence of Allah the Exalted.
And it is narrated from Shaykh al-Islam Ibn Taymiyyah (may Allah have mercy on him) that the word "Face" is a shared term—sometimes it means one thing, other times another—and all the meanings are real. Therefore, such an interpretation is not considered interpretation of ambiguous verses.
(رَبِّكَ)—Question: In another surah, the address is in dual form, but here it is singular—why?
The answer is that here the address is directed to each individual personally, so that every person may hold the belief in their own perishing and in the permanence of the Lord, the Exalted.