The 286th prohibition is that a judge is forbidden from accepting testimony from a wicked person and from acting based on his testimony.
The source of this prohibition is G‑d's statement1 (exalted be He), "Do not place your hand with a wicked person to be a corrupt witness." The Oral Tradition2 explains that this means, "Do not place a wicked person as a witness; do not place a corrupt person as a witness." This disqualifies corrupt individuals and robbers, who are invalid for testimony, as it is written,3 "Do not take a corrupt witness against any person."
The details of this mitzvah are explained in the third chapter4 of tractate Sanhedrin.
