Water barrier

Allah, the Exalted, says:

مَرَجَ ٱلْبَحْرَيْنِ يَلْتَقِيَانِ ﴿٩١﴾ بَيْنَهُمَا بَرْزَخٌۭ لَّا يَبْغِيَانِ ﴿۰٢﴾ فَبِأَىِّ ءَالَآءِ رَبِّكُمَا تُكَذِّبَانِ ﴿١٢﴾ 


يَخْرُجُ مِنْهُمَا ٱللُّؤْلُؤُ وَٱلْمَرْجَانُ﴿٢٢﴾

"He has let loose the two seas (the salt and fresh water) meeting together. Between them if 

a barrier which none of them can transgress. Then which of the Blessings of your Lord will you both (Jinn and men) deny? Out of them both come out pearl,  (Sr,AlRahman55:19-22)                                                                                                                                                                                                                                                                                                                         وَهُوَ ٱلَّذِى مَرَجَ ٱلْبَحْرَيْنِ هَٰذَا عَذْبٌۭ فُرَاتٌۭ وَهَٰذَا مِلْحٌ أُجَاجٌۭ وَجَعَلَ   بَيْنَهُمَا بَرْزَخًۭا وَحِجْرًۭ  مَّحْجُورًۭا ﴿٣٥﴾

And It is HE IS Who has let free the two seas (kinds of water), this is palatable and that is salt and bitter; and He has set a barrier and a complete partition between them."(Sr, Al-Furqon; 25: 53)

Linguistic Interpretation:

Ibnu Mundir said in Lisan  Al- Arab

Maraja (translated above as "Letloose" or "letfree" ) has two meanings; (I) mixing and (II) coming and going or uncertain movement.

Ibn Farris said in Mu'jam Maqayis Al-Luthah:

Meem, Ra' and Jeem form a sound root which is indicative of coming and going  and uncertaion vovenmen.

Al Zajjaj Said:

Maraja means mixing, i.e., between the salt water and the fresh water. What is meant is that they do not overwhelm one another, i.e.,the salt water does not overwhelm the freshwaterand mix with it.

Ujaj (translated as bitter in Sr Al-Furqon, 25:53) mean salt, or it was said that it means bitter, or very bitter. It was also said that it means very warm.

 Allah, the Exalted, says:" and that is salt and bitter" Which means that which is very salty and bitter, like sea water. Ujaj means salt water that is very salty, Ajeej Al- Ma' refers to sound of wateras itpours. 
  Hijr or hajr means stopping and restricting, Ibn Munzdhir said, "Laqadtahajjarta wasi' an" meaning, , "You are resticting something that Allah meant to be broad in scope, and made it only for yourself."


  Ibn Faris said in Mu'jam Maqayis Al-Lughah," Reason is called Hijr because it prevents one doing something inappropriate."


 A barrier between the freshwater rver and the salty sea

Al-Tabari said, what is meant by ''sweet and palatable" water is the water of rivers and rain, and "salt and bitter " refers to sea water. What is referred to is that by His Blessing to His cretion, He mixes the sweet and palatable river water with the salty and bitter sea water, then He prevents the salt from affecting or corrupting the freshness of the freshwater by His decree.

  "...and He has set a barrier.... between them " means: a barrier  which prevents either or them from spoiling the othe.

"    and a complete partition"  means: He has made it forbidden for either of them to change its counterpart. It was narrated that Mujahid said: i.e., a barrier that no one can see.

  "and He has set a barrier ...between them ''  Mujahid said: "barrier'' means that they meet  but they do not mix.''...and a complete partition'' means that they saltiness of one oes not mix with the sweetness of the other, so neither of them prevails over the other.

  

 We should point out the exegetes of the Qur'an could not have fully understood to details of what is mentioned in the Verses, because  they could not see it and examine it. This is why they had different explanations of the word "wave" barrier and complete partition. That is due to thge lack of human knowledge in past centuries.  

Historical introdution 

  The histiry of the development of oceanogrphy indicates that there was no scientific information concerning this topic; rather the scientice of oceanography did not make any progress until the last two centuries, especially in the latter half of the twentieth century. The depths of the sea were unknown to man but there were many legends and myths about them.

   Then the science of oceanography began to take its placeamong modern sciences when the British ship HMS Challenger undertook a journey around the globe during the years 1872-1876. After that there were many more scientific journeys that explored the seas.

 In the 1940s, marine studies that were carried out  at sea stations discovered that the salty sea are ot different types, and that there are barries which separate one salty sea from another.

  The study of the ocean developed furter, and satellites played a major role in these developments. Scientists were able to obtain pictures of these barriers, and also of estuaries, differences in temperature, and pollution.

Some scientific facts 

• B etween the salty seas there are water barriers that preserve the distinguishing characteristics of each sea.
•  There is some mixing between the two seas despite the presence the of the barrier, but  it is a very slow mixing, so slow  that the amount that crosses over from one sea to the other takes on the characteristics of the sea to which it moves without affecting it.
• Marine studies show that coral exists only in sea region and does not exist in freshwaterregions.
• Water may be devided into three types: river water, sea water and estuary water.
• There is no direct contact between river water and sea water in estuary regions because of the presence of the water barrier, which surrounds this region and keeps the two apart.
• The estuary region is regarded as a partition which keeps the creatures that inhabit it spsrate from the creatures that live outside it.

Scientific explanation

    In the 1940s, scientists discovered the salty seas are of different type. This was only found out after researchers set up sea stations to analyze samples of sea water. They measured differences in temperature, salinity levels, density and oxygen ratio in the water of all the oceans, and realized that the seas differ from one another. The scientists discovered the existence of water barriers, which are of two types: