"Do not place your hand with an evildoer" (Exodus 23:1). The Torah issues this warning in the context of bearing false witness, but the Mekhilta unpacks it with a vivid courtroom scenario that reveals exactly what kind of corruption the verse targets.
Picture the scheme. A man approaches you with a proposition: "That fellow owes me two hundred dinars, and I already have one witness to prove it. Come and stand as the second witness. You will receive one hundred dinars, and I will keep one hundred." The math is clean. The partnership is straightforward. And it is precisely the kind of arrangement the Torah forbids.
Jewish law requires two witnesses to establish a monetary claim in court. One witness alone cannot compel payment. The swindler in this scenario has a real witness but needs a second to complete his case. He is not asking you to fabricate testimony from nothing. He is asking you to lend your presence, your credibility, your oath — to confirm something you never actually saw.
The Mekhilta's reading transforms this verse from a general moral principle into a specific legal prohibition. "Do not place your hand with an evildoer" means: do not become the instrument that makes someone else's fraud succeed. The guilt does not belong only to the schemer. It falls equally on the person who agrees to stand beside him in court. Even if the underlying claim happens to be true, the false witness corrupts the entire system. Justice requires that every piece of testimony reflect what the witness personally knows — nothing more, nothing less.