Sefer Chasidim Siman 401
Can copy this into an AI, or connect the whole library to your assistant. For deeper learning, you can directly use the original seforim, sites, and apps.
כל המלוה לשרים המעלילים כאילו גוזל לישראל כי כשילוה לשר השר יאמר אם לא תאמין לי את המשכון אתפוש את היהודי וגם יבא לידי שבועה:
Medieval Jewish mysticism, translated by Sholom Alchanan Singer. Northbrook, Ill. Whitehall Co., 1971
Anyone who lends money to rulers who engage in libels - it is as if he robs Israel because if he lends it the ruller might tell him "Give me back my security and believe me (even without it) And if not I'll go capture a jew!". And it can end up with the ruller making an oath (in the name of idolatry).