What is the meaning of "ve'Lo Sachnifu es ha'Aretz"?
Rashi and Targum Onkelos: It means that one should not render the land guilty. 1
Ramban #1: It means that one should not make the land 2 a Chanef' (a flatterer - one who does the opposite of what appears) - If we indulge in idolatry, Arayos or murder, the curses will come, and the land will produce much seed, but we will gather little; we will plant vineyards, but not drink wine; we will have olives, but not anoint [with their oil]. 3
Ramban #2 (citing the Sifri): This is a warning (a La'av) against flattery, 4 following the La'av against taking ransom for murderers.
See Sifsei Chachamim.
Ramban: Having included Chutz la'Aretz in the laws of Mishpat- Refer to 35:29:1:2, the Torah here adds an issue that pertains exclusively to the inhabitants of Eretz Yisrael, in deference to the Shechinah that dwells there.
See Devarim 28:38-40.
What are the implications of the second half of the Pasuk "ve'ha'Aretz Lo Yechupar Ki-im be'Dam Shofcho"?
Rashi (in Zevachim, 88b) and Abarbanel (in Yeshayah 34:4): It implies that as long as the murderer has not been put to death, they are subject to punishment.
Rashbam: It implies that atonement for murder can only be achieved with the blood of the murderer 1 - and not in any other way. 2
Kerisos, 26a: It implies that if the neck of an Eglah Arufah has not been broken until Yom Kipur has passed, it must still be broken. 3
Sotah, 67b: Consequently, if, after the Eglah Arufah has been killed (See Shoftim Devarim, 21:4) the murderer is found, he must still be sentenced to death. See Torh Temimah, note 79.
And not even by taking money from the murderer in order to feed the starving orphans of the man he murdered. See Oznayim la'Torah on Pasuk 31 & 32 DH 've'Lo Sikchu Kofer' #1.
Kerisos, Ibid.: Even though Yom Kipur atones for sins of which nobody other than Hashem is aware. See Torah Temimah, note 81.