According to Cicero, what is the source of authority for legitimate laws in "The Laws"?

Cicero, in his work "The Laws" (De Legibus), argues that the source of authority for legitimate laws is rooted in nature and reason. He posits that true law is not something created by humans but is a reflection of a higher moral order or natural law. This natural law is universal and immutable, providing the foundation for justice and ethical governance. Cicero emphasizes that laws must align with this rational moral law to be considered legitimate. He also indicates that a government's legitimacy arises from its adherence to these higher principles, suggesting that laws disconnected from natural law lack true authority and moral validity. Thus, the ultimate source of authority for Cicero's legitimate laws is the rationality inherent in human nature and the natural order.