Rashi citing Targum Yonasan: The Navi says, pass and return in the gates. Turn the heart of the nation to go in the proper path.

Radak: Ivru is a command [not to anyone particular], like I explained "Solu Solu" (refer to 57:14:1:2). It is doubled to strengthen the matter. Ba'She'arim is like "Ivru va'Shovu mi'Sha'ar la'Sha'ar ba'Machaneh" (Shemos 32:27).

Malbim: In this vision, the Navi sees returning from Galus in deed. He commands to clear the Derech from obstructions (e.g. trees), like "Kol Korei ba'Midbar Panu Derech Hashem" (40:3).

Rashi: Pave the road.

Radak: Refer to 57:14:3:2-3.

Malbim: Derech is the fixed path for the Rabim. On its side, they are Mesolel (raise it) via rocks and sand, so it is called Mesilah. After clearing the Derech, raise the Mesilah.

Rashi #1: Remove the rocks that are stumbling blocks from the path, i.e. the Yetzer ha'Ra.

Rashi #2, Radak #2, Malbim: This refers to fixing the roads for the gathering of exiles (remove the stumbling blocks).

Radak #1: Put stones [on roads that are ruined via mud, to raise them; it is normal to do so]. Me'Even means to take big rocks.

Rashi: It is a banner - a sign that they should gather to Me, and bring to Me the exiles by them ¹ . Radak - all this is a metaphor. It is like saying 'clear a path for Ploni, who is coming.' When the time of salvation comes, the nations will tell Yisrael 'go return to your land', as if they lifted a banner for them. The salvation will be revealed so much to everyone.