Rashi #1: Compared it to a prince who, unable to retain the disgusting food that he had been fed, vomited it ? it means that Eretz Yisrael cannot retain those who sin, so it vomits out ¹ those who desecrate it (empties itself from them - Rashi citing Targum Onkelos).

Rashi #2, in Seifer ha'Pardeis: It teaches us that the land itself does not tolerate a 'Tamei person' ? such as the people of the seven nations, is pained when people who live in it sin and vomits them. ²

Hadar Zekenim, Moshav Zekenim citing Bechor Shor, Riva citing R"M of Kutzi: Do not think that the only punishment will be expulsion, like it was for the Kena'anim. Rather, also, the sinners will receive Kares.

Shabbos, 33a: The Torah is teaching us that the punishment for Giluy Arayos is Galus, ³ and that others will come and live in the land. ⁴

Riva #1: This refers to verse 26. Guard My Chukim, and the land will not expel you.

Riva #2: [If you sin] the land will not expel you like it expelled the Kena'anim - it will be worse. ⁵ Rosh - this is because you enter the land with a tradition and a covenant.

Riva #3: [If you sin] the land will not expel you like it expelled the Kena'anim. It suffices that you will receive Kares.