Surah Al-Furqan Verse 53 - English Translation by Shabbir Ahmed
Surah Al-Furqan۞وَهُوَ ٱلَّذِي مَرَجَ ٱلۡبَحۡرَيۡنِ هَٰذَا عَذۡبٞ فُرَاتٞ وَهَٰذَا مِلۡحٌ أُجَاجٞ وَجَعَلَ بَيۡنَهُمَا بَرۡزَخٗا وَحِجۡرٗا مَّحۡجُورٗا
And He it is Who has given freedom of movement to the two kinds of great bodies of water; one is palatable and fresh, the other salt and bitter. Yet, He has made a barrier between them, a partition that is not to be passed. (35:12). (Please see (18:60) for two streams in a different implication