Rashi on Deuteronomy 16:19/רש"י על דברים ט״ז:י״ט

1לא תטה משפט means what it literally implies: THOU SHALT NOT PERVERT JUDGMENT.

2ולא תכיר פנים AND THOU SHALT NOT RESPECT PERSONS — not even if it be only during the pleadings of the parties. This is an admonition addressed to the judge that he should not be lenient to one and harsh to the other, e.g. letting one stand and the other sit; because as soon as he (the party treated harshly) observes that the judge shows more respect to his fellow his ability to plead is hampered (i.e. he loses self-confidence and cannot present his case with assurance) (cf. Shevuot 30a).

3ולא תקח שחד NEITHER TAKE BRIBERY — even if you mean to give a just judgment in favor of the giver (Sifrei Devarim 144:10; cf. Rashi on Exodus 23:8).

4כי השחד יעור FOR BRIBERY DOES BLIND — As soon as he (the judge) has accepted a bribe from him (from one of the parties) it is impossible for him not to incline his heart to him trying to find something in his favor (Ketuvot 105b).

5דברי צדיקם means, the words which have been described by the term “righteous” viz., the judgments of truth uttered on Sinai (cf. Rashi on Exodus 22:8 and Note thereon).