Q: Are rulings issued by civil courts, such as Supreme Court decisions, included in dina d’malchusa?
A: Dina d’malchusa applies to laws and rules established by the king or legislative body of the government. However, laws and rules advanced by civil courts are not included in dina d’malchusa, even if the law requires following their rulings. Civil judicial rulings do not have authority to usurp Torah law for dealings between Jews (Sma 369:21).
Moreover, even if the ruling is the court’s interpretation of the law, when this interpretation is unclear and subject to the judge’s personal understanding, especially if guided by worldviews contrary to Torah perspective, dina d’malchusa does not apply (Tzitz Eliezer 16:49).
Thus, even a Supreme Court ruling, which is not based on a clear reading of the law as intended by the lawmakers, does not carry the status of dina d’malchusa. Nonetheless, on contractual issues, the rulings can form a common commercial practice if they become entrenched and are accepted in practice among Jews as well (Responsa Rashba 3:109, 6:149).