أَوْتَادًا (stakes): They are used for fastening. It was a practice to fix the ropes of tents to the earth.
The Holy Qur’an contains scientific secrets in a way that they do not collide with the human intellect, and especially the intellect of those whom the Holy Qur’an had been revealed upon during the first period.
What do these pegs fix? So there is something movable needs to be fixed.
The mountains make firm the Earth in its movements. Had the Prophet (saws) or the Holy Qur’an said that the Earth is moving, no one would accept this fact at that time. Hence, Allah (swt) says (as stakes) not (as if they were stakes), this reflects the accuracy in the Arabic language. The mountains are really stakes, not as if they were stakes. They make firm the Earth when it goes around itself and around the sun. So these stakes: First, fix the movement of the earth, second, they fix the Earth’s crust sheets, otherwise, they would crack.
The verses in the beginning talk about the Day of Judgement by talking about the unseen. Then, the verses which follow talk about things which can be seen. This is to prove to us the certainty of occurrence of the things which we will be seeing as if we were seeing them this instance.
The Holy Qur’an comes with scientific facts that have not been proved until the 20th century.