﴿ فَلَمَّا بَلَغَا مَجْمَعَ بَيْنِهِمَا نَسِيَا حُوتَهُمَا فَٱتَّخَذَ سَبِيلَهُۥ فِى ٱلْبَحْرِ سَرَبًۭا ﴾

“But when they reached the junction between the two [seas], they forgot all about their fish, and it took its way into the sea and disappeared from sight.”

(And when they reached the point where the two met) between the two seas, (they forgot their fish) they forgot the matter of their fish, (and it took its way into the waters, being free).