فَلَمَّا بَلَغَا مَجۡمَعَ بَيۡنِهِمَا نَسِيَا حُوتَهُمَا فَٱتَّخَذَ سَبِيلَهُۥ فِي ٱلۡبَحۡرِ سَرَبٗا ٦١
But when they reached the junction between them, they forgot their fish, and it took its course into the sea, slipping away.
Translation: Saheeh International (English)
Each word's meaning and sound
So they both travelled and when they reached the place where the two seas meet, they forgot the fish that they had carried as provision. Allah gave life to that fish and it made a pathway in the sea like a tunnel, with which the water did not come together.
Al-Mukhtasar in interpreting the Noble Quran