And it is He who has released [simultaneously] the two seas, one (25:53)

Almuntakhab Fi Tafsir Alquran Alkarim

And He is it Who sent the waters of the two seas flowing together, one fresh and sweet and the other salty and bitter and between both He installed an invisible partition which serves as an impassable barrier (the fresh water floats above the salty and there are laws that govern the separation and the depth)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(25:53) And it is He, Who has let loose the two seas, one palatable and sweet, the other bitter and saltish, and there is a partition between them, which is an insurmountable barrier. *68

And it is He who has released [simultaneously] the two seas, one meaning

*68) This phenomenon has been perceived in many places in the sea and on the land that sweet water and bitter water has existed side by side. Turkish Admiral Syedi Ali Ra'is, in his book Mir 'at-al-Mamalik, written in the 16th century, has mentioned a place in the Persian Gulf, where springs of sweet waver exist under the bitter waters of the sea, where he could get drinking water for his fleet. The American Oil Company at first obtained water from the same springs in the Persian Gulf, before they dug up wells near Dhahran for supply of drinking water. Near Bahrain also there exist springs of sweet water at the sea bed from which people have been taking water until quite recently. Besides this apparent meaning which gives a rational proof of Allah's being the One and the only Lord of the universe, the verse contains a subtle suggestion as well: When Allah wills, He can raise up a righteous community from among a large wicked society just as He can cause springs of palatable and sweet water to gush out from under the salty waters of the sea.
 

And it is He who has released [simultaneously] the two seas, one meaning in Urdu

اور وہی ہے جس نے دو سمندروں کو ملا رکھا ہے ایک لذیذ و شیریں، دوسرا تلخ و شور اور دونوں کے درمیان ایک پردہ حائل ہے ایک رکاوٹ ہے جو انہیں گڈ مڈ ہونے سے روکے ہوئے ہے