Allah says:
Have We not made the earth as a bed, and the mountains as pegs? (78:6-7)

Scientists explain the importance of mountains as being pegs which stabilize the earth saying:
“Mountains have underlying roots. These roots are deeply embedded in the ground, thus, mountains have a shape like a peg. The earth’s crust is thirty to sixty kilometers deep, this being known due to the seismograph. Also, it is known due to this machine that every mountain has an underlying root, which stabilizes the crust of the earth with the underlying layers, and prevents the earth from shaking. Therefore, the mountain is similar to a nail, which holds different pieces of wood together.” (1)

Allah says: And He has affixed into the earth, mountains standing firm, lest it should shake with you; and rivers and roads, that you may guide yourselves (16:15)

Modern science attests to the fact that mountains are distributed evenly and perfectly on earth, which also stabilize the earth, especially those mountains which the geologists call “Asymmetrical Mountain Ranges” which are to be found in every continent. How then could an unlettered man, whose nation was mostly unlettered, know these facts?