Why did Moshe repeat the fact that he was unable to judge the people single-handedly (See Pasuk 9)?
Rashi: Even if, in spite of the potential punishment for judging alone, 1 he would be willing to do so, he would not be able to since, as he already informed them, 2 the decision was not his, but Hashem's.
Seforno: The gist of the Pasuk is to rebuke the people on the fact that, even after informing them of their imminent entry into Eretz Cana'an, 3 they continued to squabble over monetary issues, until it reached a point that he had to organize judges and even to go so far as to appoint one judge for every ten people. 4
What is the definition of "Torchachem, Masa'achem" and "Rivchem"?
Rashi (citing the Sifri): "Torchachem" is where, for example, one of the litigants, seeing that the other side was winning the case, would claim that he had more witnesses, more proofs or that that he wanted to add more judges; "Mas'a'achem" is where, when Moshe left the Beis-Din early, they would accuse him of having trouble with Shalom Bayis, whereas "Rivchem" means simply their quarrelsomeness.
Ramban #1: They refer to the three things that Moshe told Yisro 1 with reference to his status as the sole judge 2 : 1. To Daven on their behalf ("Masa'achem"), 3 2. To teach them Torah ("Torchachem"), 4 and 3. To litigate between the quarreling parties ("Rivchem").
Seforno: "Torchachem" refers to their quarrels over general issues, "Mas'a'achem", to communal affairs and "Rivchem", to quarrels over money-matters.
Targum Yonasan: "Torchachem" refers to matters concerning herecy, 5 "Mas'a'achem", to their wicked thoughts concerning himself, 6 and "Rivchem", to their devious behavior in court, where they would give a Sela in order to extract two, 7 or two, to extract three.