Targum zu Dewarim 1:16

And I charged your judges at that time with the orders of judgments, saying: So hear your brethren that one may not (be permitted to) speak all his words, while another is compelled to cut his words short; and so hearken to their words, as that it may be impossible for you not to judge them, and deliver judgment in truth, and to resolve (a matter) completely between a man and his brother, and between him who hireth words of litigation.