Why is "go down" repeated?

Imām Ibn al-Jawzī (d. 597/1201) summarized the scholars' opinions in his book "Zād al-Masīr" as follows:

1. The repetition is because Adam made two descents: one from Paradise to the (worldly) sky, and the other from the sky to the Earth. There is difference of opinion as to which of these two descents is referred to in this verse.
2. It was repeated for emphasis (of the same descent).