What do we learn from "veha'Aretz Nasan li'Venei Adam"?
Yevamos 63a: One who does not own land is not considered a person.
Here it says that Hashem gave the land to man. It says also "la'Shem ha'Aretz u'Melo'ah" (24:1) and "Li ha'Aretz" (Vayikra 25:23)!
Brachos 35a: Before one blesses, everything belongs to Hashem; after one blesses, it is considered his.
Gitin 47a: A Nochri cannot acquire land in Eretz Yisrael to exempt it from Ma'aser (for Kedushah ha'Aretz is of Hashem), but he can acquire it to dig pits in it.
What do we learn from the contrast of Shamayim and Eretz?
Sukah 5a: The Shechinah never descended [below 10 Tefachim], and Moshe and Eliyahu did not ascend [above 10].
Radak: Even though Hashem alone rules over Shamayim, He authorized people to rule in the land - "Tamshilehu b'Ma'asei Yadecha Kol Shatah Sachas Raglav" (8:7). People must realize that He is Master of all, and they are His appointees. When He wants, He will remove them from their posts and give them to others, i.e. kill the former and cause others to be born. One who recognizes this and fears Him, he will live the time allotted for him.
Malbim: Hashem's conduct of Shamayim is attributed to Him. It is based on His will and general conduct, based on the laws that He established - "vEi'lokeinu ba'Shamayim Kol Asher Chafetz Asah" (3). Every day He renews the creation. What He does in the land is according to people's choice - Avodas Hashem or rebellion.
