Tafseer Ibn Kathir of AN NAHL [15]

وَأَلْقَى فِي الأَرْضِ رَوَاسِيَ أَن تَمِيدَ بِكُمْ وَأَنْهَارًا وَسُبُلاً لَّعَلَّكُمْ تَهْتَدُونَ

And He has cast into the earth firmly set mountains, lest it shift with you, and [made] rivers and roads, that you may be guided,