What do we learn from "Beni Im Aravta..."?
Rashi citing Bava Basra 173b: If you were a monetary guarantor - refer to 6:3:2:1.
Rashi (3): After you became an Arev to Hashem, who is Re'echa - "Zeh Dodi v'Zeh Re'i" (Shir ha'Shirim 5:16), and you accepted on yourself in Sinai and Arvos Mo'av with a curse and Shevu'ah to guard his Mitzvos.
Malbim: If you were an Arev to your friend to do something, and afterwards "Takata la'Zar Kapecha" (shook hands with a stranger to do oppositely) - e.g. you accepted to sell a house or field, and afterwards shook hands with a stranger and agreed to sell it to him, there is an Arev and an Arev Kablan. Shaking hands is more than Arvus.
Malbim (5, according to Melitzah) #1: Everyone is an Arev to Hashem to guard His Mitzvos - 'ha'Kol Nasun b'Eravon' (Avos 3:16).
Malbim (5, according to Melitzah) #2: Everyone is an Arev to guard His Neshamah in Taharah.
Why does it say "Takata la'Zar Kapecha"?
Rashi: You will return to veer from your ways and cling to Apikorsim to go in their ways.
Malbim: Refer to 6:1:1:1.
Malbim (5): [After accepting Arvus to Hashem,] he shook hands with a Zar - the Yetzer ha'Ra, or physicality that desires to be drawn after it - the opposite of his Arvus.
