Why does the Torah now discuss theft and related Mitzvos?
Seforno (in Pasuk 9): Because just as it is befitting to go in Hashem's ways and to perform Tzedakah and Chesed, so too should one follow in His footsteps and carry out justice. 1
Refer to 19:9:3:2.
Oznayim la'Torah: Because, if a Ba'al ha'Bayis justifies taking Leket, Shikchah and Pe'ah for himself - bearing in mind that he worked on the field whereas his poor partners 2 did not, he will go on to steal from others - even where he cannot justify it..
Why does the Torah insert the La'av of 'Lo Tignovu'? Why can we not learn it from Ribis and Ona'ah (which also come to deprive one's fellow-Jew of his money)?
Bava Metzi'a, 61b: To incorporate someone who steals in order to hurt the owner, but having in mind to return it, or with the intention of paying Kefel (double). 1
See Torah Temimah, note 60, and Oznayim la'Torah, who elaborate.
Having taught "Lo Tignov" in the Aseres ha'Dibros, why does it repeat it here?
Rashi: Because whereas there it is referring to kidnapping people, 1 here it is referring to stealing objects. 2
Refer to 20:13:2:1*.
Sanhedrin, 86a: As is evident from the continuation of the Pasuk. See Torah Temimah, note 61.
What are "Lo Sechachashu" and "Lo Seshakru" referring to?
Rashi: "Lo Sechachashu" is the Azharah (the warning) that precedes "ve'Chichesh bah" in Vayikra, 5:22, 1 and "Lo Seshakru", the Azharah that precedes "ve'Nishba al Shaker" in the same Pasuk.
Rashbam: "Lo Sechachashu" refers to denying having received a Pikadon (a deposi) and "Lo Seshakru", to denying having borrowed money.
Seforno: All the La'avin in this Pasuk and in the following two Pesukim all apply to causing one's fellow-Jew a monetary loss. 2
What is the significance of the sequence of the La'avim in this Pasuk?
Rashi: Someone who steals, will ultimately deny, then lie, then swear falsely.
Rashbam: Refer to 19:11:3:2.
Why are "Lo Signovu" and "Lo Sechachashu" written in the plural?
Moshav Zekenim (in Pasuk 9): One who sees and is quiet is also [considered] a thief. Similarly, one who knows about someone who denies a deposit and fails to testify is [considered] a denier.