Surah Al-Furqan — Ayah 53 (25:53)
۞ وَهُوَ ٱلَّذِي مَرَجَ ٱلۡبَحۡرَيۡنِ هَٰذَا عَذۡبٞ فُرَاتٞ وَهَٰذَا مِلۡحٌ أُجَاجٞ وَجَعَلَ بَيۡنَهُمَا بَرۡزَخٗا وَحِجۡرٗا مَّحۡجُورٗا ٥٣
English translation (Saheeh International)
And it is He who has released [simultaneously] the two seas [i.e., bodies of water], one fresh and sweet and one salty and bitter, and He placed between them a barrier and prohibiting partition.
Brief commentary
It is Allah, may He be glorified, who merged the water of the two bodies of flowing water. He mixed the sweet and the salty, and put a barrier and dividing line between them that prevents them from intermingling.