Why does it say "Yoshevei he'Charavos ha'Eleh"?
Radak: During Tzidkiyah's kingship, most of Eretz Yisrael was desolate.
Malbim: After the Churban, many Yisraelim lived in ruins, fields and caves. They thought that there will still be settlement in Eretz Yisrael, and Kedushas Eretz Yisrael did not cease at the time of the Churban. The Navi told them that the land will be totally desolate ? "me'Of ha'Shamayim v'Ad Behemah Nadedu Halachu" (Yirmeyah 9:9), and that the Kedushah ceased at the time of the Churban ? the first Kedushah was temporary, and not permanent (Eduyos 8:6). Refer to 33:24:2:4.
What do we learn from "Echad Hayah Avraham"?
Rashi citing Sifri Va'eshchanan 31: This is one of four matters that R. Akiva expounded, and R. Shimon disagreed. R. Shimon expounded, Avraham was commanded only one Mitzvah, and he inherited the land. We were commanded many Mitzvos ? all the more so it should be an inheritance to us!
Radak: Avraham was one, and he inherited the land; Hashem gave it to him ? "Lases Lecha Es ha'Aretz ha'Zos Lerishtah", and he said "ba'Mah Eda Ki Irashenah" (Bereishis 15:7-8). Even though one place would have sufficed for him, he inherited [the entire land]. We are many ? all the more so it is proper that we inherit it!
Radak citing R. Akiva in Sifri Va'eshchanan 31: Avraham served only one G-d, and he inherited the land. We serve many gods ? all the more so we should inherit it!
Malbim: Yoshevei he'Charavos made this Kal v'Chomer to shows that Kedushas Eretz Yisrael did not cease. Avraham was an individual who believed in Hashem, and his merit caused him to inherit the land, which he did not own beforehand. We are many who believe, and the land was already given to us for an inheritance ? surely the inheritance is not Batel!
Why does it say "l'Morashah"?
Radak: It was given to Avraham, only so that it will be an inheritance for us.
Why does Bereishis Rabah 92:7 not list this among the 10 Kal va'Chomerim in Tanach?
Refer to 15:5:3:1.
