R. Yonah: [They are fraudulent scales,] like it says "Lo Yihyeh b'Kischa Even va'Aven", "Ki To'avas Hashem Elokecha Kol Ose Avel" (Devarim 25:13, 16).

R. Yonah: It seems that he proves how hated is "Pi Resha'im Tahpuchos" (10:32). Even if the Rasha's vindication of the false claim has no effect, for he is not a judge between them, and he cannot save the oppressed from the oppressor, even so it is To'avas Hashem. This is like a fraudulent scale, which is To'avas Hashem even if he did not weigh with it. One transgresses from when he made it (Bava Metzi'a 61b); the Torah already forbids theft and overcharging! All the more so vindicating Sheker is To'avas Hashem, even if it did not damage. Both of them are prepared to help Sheker. Habit rules over the heart and lips - 'habit rules over all', "Limedu Leshonam Daber Sheker" (Yirmeyah 9:4), "ha'Omerim la'Ra Tov vela'Tov Ra" (Yeshayah 5:20).

Malbim: This teaches that veering from evil is itself doing good. Even though Mozenei Mirmah are a To'evah, do not think that having a proper rock (weight) is not doing To'evah and merely veering from evil. This is doing Hashem's will, and it is considered that he did a Mitzvah. If one was passive and did not transgress, he is rewarded like one who did a Mitzvah (Kidushin 39b).