Sura 18 Al-Kahf (The Cave), ayah 60

1. وَإِذْ قَالَ مُوسَىٰ لِفَتَاهُ لَا أَبْرَحُ حَتَّىٰ أَبْلُغَ مَجْمَعَ الْبَحْرَيْنِ أَوْ أَمْضِيَ حُقُبًا

   And (mention) when Moses said to his servant, "I will not cease (traveling) until I reach the junction of the two seas or continue for a long period."

   18:60

Translation: Saheeh International