Komentarz do Rodzaju 13:17

ARISE, WALK THROUGH THE LAND IN THE LENGTH AND IN THE BREADTH OF IT. It is possible that this is a matter of option, depending on his will.¹⁰⁹It is not a command that he go through the entire land, rather it is a promise that he need not fear whenever and wherever he will go. The Eternal thus told Abraham, “Go wherever you wish to go in the land for I will be with you and guard you from the evil of the nations, for unto thee will I give it, that is to say, the land will be yours.” And if it be a command that Abraham should traverse the length and breadth of the land in order to take possession of his gift, as I have explained,¹¹⁰Above, 12:6. he was not commanded to do this immediately. He did so ultimately for he was now in the east, and afterwards he went to the land of the Philistines which is in the west, and thus he fulfilled the command during his lifetime.
The meaning of the expression, to thee… and to thy children,¹¹¹Verse 15 here. is that you are to take possession of the gift now, in order to transmit it to your children, even as our Rabbis have said:¹¹²Baba Bathra 119b. “The land of Israel is an inheritance to the people of Israel from their patriarchs.”
By way of the plain meaning of Scripture, it is possible that the meaning of the verse is that Abraham was to be a ruler over the land and a prince of G-d in its midst,¹¹³See Genesis 23:6. wherever he will go in this land.

קום התהלך בארץ. "Arise, and walk through the land." The Talmud Baba Batra 100 discusses how one acquires title to land. [The context of the discussion is whether the fact that people used someone's private property as a shortcut entitles them to continue to do so even if the property in question changed hands. Ed.] Rabbi Eliezer, basing himself on our verse, claims that merely traversing the land assures one of one's rights to the area one has traversed; the other rabbis hold that one has to go through the regular legal procedure for acquiring title. The rabbis say that our verse is not to be taken as a general rule, but that an exception was made in the case of Abraham who was especially beloved of G'd. G'd intended to facilitate Abraham's descendants taking possession of the land when the time came. According to these rabbis, Abraham's title to the land stems from verse 15 where G'd had promised it to Abraham. The reason G'd rolled the land up so as to bring it close to Abraham was in order that the act of moving it would demonstrate ownership by the person on whose behalf it was moved.

לארכה, according to its length, from east to west; ולרחבה, and to its width from north to south.