Al-Kahf 18:60

Wa-ith qala moosa lifatahula abrahu hatta ablugha majmaAAa albahrayniaw amdiya huquba

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

(Recall) when Mūsā said to his young man, “I shall not give up until I reach the meeting point of the two seas, or else I shall go on traveling for years.”