Midrasch zu Mischlej 24:23

Now these are the ordinances (Exod. 21:1). Scripture says (elsewhere) in reference to this verse: These also are sayings of the wise. To have respect of persons in judgment is not good (Prov. 24:23). The Holy One, blessed be He, said to Israel: Remember that I gave you the Torah, in which is written: These are the statutes and commandments. To have respect of persons in judgment is not good. What is meant by this? If a judge acts differentially toward a particular witness and perverts the law because of him, the Shekhinah departs (from him), for it is written: The Lord is good to all (Ps. 145:9). Because of that it is written: God standeth in a congregation of God; in the midst of judges He judgeth (ibid. 82:1).