ידע לכתך, He repaired or improved that way wherever necessary. The word ידע is used here in the same sense as in Exodus 5,25 וידע אלוקים, where it meant that G’d took benevolent notice of the plight the Israelites were in and began to rectify their situation. Similar uses of the term are found in Exodus 33,12 where Moses is the beneficiary of such ידיע, and in Deuteronomy 34,10 where he is again described as the beneficiary of such a ידיע, intimate familiarity with G’d.

האימים לפנים, seeing that the descendants of Lot had no legal claim to inherit anything from Avraham at all, G’d announced that He had given them ancestral land just as He had done to the descendants of Esau who were descended from Avraham in a straight line. G’d testifies that both the Ammonites and the Moabites came to possess what they owned contrary to accepted norms.

וישמידום. Esau and Moav destroyed more land and people than they needed for themselves. They did so in order to wipe out all the former people residing there so that they could not one day avenge their defeat. This was a totally unjustifiable genocide. Neither Esau nor Moav populated all the land under their control The area known as Har Seir bordered on areas formerly belonging to Moav and was unpopulated by any members of the tribe of Esau. The same was true on the other side of that boundary; it was not populated by any Moabites. This is why Moses is speaking of G’d having told him that although this was in effect “no-man’s land,” the Israelites were not even to traverse this region, as, nominally, it belonged to either the descendants of Lot or those of Esau.

כאשר עשה ישראל, a reference to the time when the Torah was committed to writing when the lands of Sichon and Og had already been captured. Those two kings had been most powerful; nonetheless, they had been vanquished within a very short space of time, contrary to accepted norms. This all showed that G’d had given these lands to the Israelites.

עתה קומו, seeing that it is forbidden to you to cross territory belonging to either the Moabites or the Edomites, קומו ועברו לכם את נחל זרד, which is outside the territory of either one of these nations. From that point you will be able to advance as far as the Jordan.

ארץ רפאים תחשב אף היא, there can be no question that the Ammonites had no legal right to dispossess these people; the only reason why they succeeded in doing so was because it was G’d’s will.

כאשר עשה לבני עשו, just as G’d had done for the descendants of Esau who, after settling in the land of Seir, had driven out the inhabitants (the Chori) from there.

והעוים היושבים בחצרים עד עזה, even though the latter belonged to the descendants of Esau or the Philistines with whom Avraham had made a solemn non aggression pact, the Israelites were not now denied the right to conquer these lands. The reason they could do so now was that the Philistines no longer owned the land in question כפתורים היוצאימ מכפתור, the Cretans emigrating from Crete because their island could not contain them all and who were seeking “lebensraum,” had annihilated the Avim and replaced them in that land. When the Israelites conquered the land in which Avimelech used to be king, it already had been lost by Avimelech. [Perhaps the reason that this coastal strip was still known as “the land of the Philistines,” long after the Israelites drove out the Canaanites, is the same as when the Torah referred to the land of the descendants of Ammon as “the land of the Refaim,” (verse 20) the latter having been its original owners.” Ed.]

כי הקשה ה' אלוקיך את רוחו, in order for him to refuse to allow the Israelites to traverse his territory.

ואמץ את לבבו, in order to make war against them.