Komentarz do Powtórzonego Prawa 2:1

ונפן ונסע המדברה THEN WE TURNED AND JOURNEYED INTO THE WILDERNESS — If they had not sinned, they would have passed by the way of Mount Seir to enter the Land from its south to its north, but because they became degenerate they had to turn towards the wilderness which is between the Red Sea and the south of Mount Seir, and they proceeded along its southern side from the west to the east, דרך ים סוף BY THE ROUTE FROM THE RED SEA — i.e. by the route which they had taken on leaving Egypt which is at the south-west corner. From there (where they were at that moment) they went towards the east.

Had they not sinned, etc. Meaning: Due to their sin, Hashem did not manipulate the King of Edom’s heart to allow them to pass through his land.

Kap. 2. V. 1. ונפן וגו׳ (siehe zum vorigen Verse). ימים רבים, ebenfalls neunzehn Jahre nach סדר עולם (daselbst) י׳׳ט שנה היו חוזרין ומטורפין.

ונפן ונסע המדברה דרך ים סוף כאשר דבר, “we turned around and journeyed into the desert in the direction of the sea of reeds, as G-d had said.”

ונסב את הר שעיר AND WE COMPASSED MOUNT SEIR, the whole of the south side as far as the land of Moab.

The route they traveled when leaving Egypt, etc. Rashi is answering the question: “By way of the Reed Sea,” implies that they traveled from north to south, along the Reed Sea. Yet, they traveled from west to east in the wilderness! For this reason, Rashi explains: “The route they traveled when leaving Egypt,” i.e., when they left Egypt, they traveled diagonally towards the Reed Sea from west to east. Now, also, they traveled in the same direction, for they abandoned traveling the shorter route from south to north. Instead they traveled along the southern border of Edom, from west to east, until they came to the border of Moav.

[We traversed] its entire southern rim. One should not say that they circled Mount Seir on all four sides, and this is not possible. For otherwise Moshe would have entered the Land of Israel, because the land of Edom is on the border of the Land of Israel, as explained in the demarcation of the Land’s borders (Bamidbar 34:3). Therefore, Rashi explains: Only its entire southern rim, until the land of Moav (Maharan).