Al-Kahf 18:93

Hatta itha balaghabayna assaddayni wajada min doonihima qawman layakadoona yafqahoona qawla

Until, when he reached [a pass] between two mountains, he found beside them a people who could hardly understand [his] speech.

until when he reached between the two mountains, he found by them a people who were almost unable to understand anything said.