Sforno on Deuteronomy 1:12/ספורנו על דברים א׳:י״ב

1טרחכם, your petty arguments which did not even involve financial claims.

2ומשאכם, your bicckering involving the provision of the needs for the many.

3וריבכם, and your mutual financial claims upon one another. He reminded them of all this in order that they should remember their sins. He hoped that the people repented their past conduct honestly, for in the past, in spite of Moses having told them that they would take over the land of Canaan without even having to fight for it, something that should have been their major concern seeing that they were in the desert. Rather than focusing on their major problem, how to get out of the desert into the promised land, they had wasted their time and efforts in the pursuit of petty concerns, undermining their inter-personal relationships in the process. Due to this interminable quarreling, Moses had been forced to appoint a large number of judges that had to exert authority over the individuals down to every 10 people requiring at least one such judge. This could only have been due to some character weakness, some pre-disposition to be quarrelsome.