Surah An Nahl Tafseer

وَأَلْقَى فِي الَارْضِ رَوَاسِيَ أَن تَمِيدَ بِكُمْ

And He has driven firm standing mountains into the earth, lest it should shake with you;

Allah mentions the earth and how He placed in it mountains standing firm, which make it stable and keep it from shaking in such a manner that the creatures dwelling on it would not be able to live. Hence Allah says,

وَالْجِبَالَ أَرْسَـهَا

And the mountains He has fixed firmly. (79:32)

وَأَنْهَارًا وَسُبُلً

and rivers and roads,

meaning He has made rivers which flow from one place to another, bringing provision for His servants.

The rivers arise in one place, and bring provision to people living in another place. They flow through lands and fields and wildernesses, through mountains and hills, until they reach the land whose people they are meant to benefit. They meander across the land, left and right, north and south, east and west - rivers great and small - flowing sometimes and ceasing sometimes, flowing from their sources to the places where the water gathers, flowing rapidly or moving slowly, as decreed by Allah. There is no god besides Him and no Lord except Him.

He also made roads or routes along which people travel from one land or city to another, and He even made gaps in the mountains so that there would be routes between them, as He says:

وَجَعَلْنَا فِيهَا فِجَاجاً سُبُلً

And We placed broad highways for them to pass through. (21:31)

لَّعَلَّكُمْ تَهْتَدُونَ

that you may guide yourselves