What do we learn from "Kena'an b'Yado Moznei Mirmah"?
Pesachim 50a: This teaches that Kena'ani ("va'Yar Sham Yehudah Bas Ish Kena'ani" ) is a merchant.
Rashi: You rely on your theft, that you are merchants and swindlers, and on your wealth. You say "Ach Asharti" (9), and I will not serve Hashem.
Radak: You are not like this (to guard Chesed and Mishpat, and hope to Hashem). rather, like a merchant with fraudulent scales.
Radak citing Targum Yonasan: Do not be like merchants...
Malbim: Until now explained "Sevavuni v'Chachash Efrayim" (1) - their denial of Hashgachah Pratis, and heresy to serve Sarei ha'Ma'arachah. Now it explains "uv'Mirmah Beis Yisrael" (ibid.) - they sinned Bein Adam l'Chavero with deception and overcharging.
What is the significance of "La'ashok Ahev"?
Radak: This is the opposite of "Chesed u'Mishpat Shemor" (7).
Malbim: This merchant holds fraudulent scales because he loves to oppress (cheat).