Murray Harris writes "There was what Philo calls a 'law with regard to ambassadors' (De Vita Mosis 1.25)".
However, that reference reads "(25) And when he had passed the boundaries of the age of infancy he began to exercise his intellect; not, as some people do, letting his youthful passions roam at large without restraint, although in him they had ten thousand incentives by reason of the abundant means for the gratification of them which royal places supply; but he behaved with temperance and fortitude, as though he had bound them with reins, and thus he restrained their onward impetuosity by force." (Yonge, C. D. with Philo of Alexandria. (1995). The works of Philo: complete and unabridged (p. 461). Peabody, MA: Hendrickson.)
But I don't see anything like Murray Harris' quote in the referenced passage...Any ideas?