What is the connection between this verse and the previous one?
Metzudas David: Guard the Torah, and do not come to do like these nations do.
Malbim: If you guard the Torah, you will ensure that you not intermarry with these nations.
Why does it say "ba'Goyim ha'Eleh ha'Nish'arim ha'Eleh"?
Malbim: Goyim ha'Eleh are those already conquered. Ha'Nish'arim ha'Eleh are those not yet conquered.
What is the Perush of "v'Lo Sashbi'u"?
Radak: Do not make your fellow Jew swear [in the name of their gods].
Why does the verse mention these matters?
Malbim: If you intermarry with them, you will come to progressively worse matters