Surah Al-Furqan, ayah 53

25:53

۞ وَهُوَ ٱلَّذِي مَرَجَ ٱلۡبَحۡرَيۡنِ هَٰذَا عَذۡبٞ فُرَاتٞ وَهَٰذَا مِلۡحٌ أُجَاجٞ وَجَعَلَ بَيۡنَهُمَا بَرۡزَخٗا وَحِجۡرٗا مَّحۡجُورٗا ٥٣

Wahuwal-ladhī marajal-bahrayni hādhā 'adhbun furātun wahādhā milhun ujājun waja'ala baynahumā barzakhan wahijram mahjūrā

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.