The Greek that is often translated into English as “they are a law to themselves” is translated into Bilua as “they follow their own law.” (Source: Carl Gross)
In Huehuetla Tepehua it is translated as “it is just as if they had a law in their hearts,” in Highland Totonac as “on their own they think of the law they should do,” in Yatzachi Zapotec as “what their head-hearts tell them to do is like the law for them,” in Chicahuaxtla Triqui as “their very hearts is a law which issues orders to them,” in Tzeltal as “it is because there are commandments in their hearts,” and in Sierra de Juárez Zapotec as “show that they themselves know what they ought to do.” (Source: Waterhouse / Parrott in Notes on Translation October 1967, p. 1ff.)