(15–16) “He has set firm mountains upon the earth lest it shake beneath you, and rivers and roads so that you may find your way, as well as landmarks; and by the stars they find their way.”

That is, for the sake of His servants, Allah Most High “has set firm mountains upon the earth”—great mountains—lest it sway beneath them and convulse with its inhabitants. Thus, they are able to cultivate the land, build upon it, and travel across it.

It is also part of His mercy that He placed rivers upon the earth, directing them from distant lands to regions in desperate need of them, so as to provide water for the people, their livestock, and their crops. Some rivers flow across the earth’s surface, while others run beneath it. People reach the latter by digging, then draw out their water using the water-lifting devices, implements, and other means that Allah has subjected to their service.

It is likewise part of His mercy that He made roads upon the earth—that is, routes leading to faraway lands—“so that you may find your way” to them. You may even find a land crisscrossed by continuous mountain ranges, yet Allah has made openings and pathways between them for travelers.