According to a Frisian legend recorded in the 14th century, twelve asegas were originally given the Lex Frisionum, the written law of Friesland, by the god Fosite after Charlemagne had demanded they recite their law and they were unable to do so, having only custom. This is an indication of the close relationship of ancient Germanic law to religion.
Source: Asega – Wikipedia
There is also a late-medieval legend of the origins of written Frisian laws. Wishing to assemble written lawcodes for all his subject peoples, Charlemagne summoned twelve representatives of the Frisian people, the Āsegas (‘law-speakers’), and demanded they recite their people’s laws. When they could not do so after several days, he let them choose between death, slavery, or being set adrift in a rudderless boat. They chose the last and prayed for help, whereupon a thirteenth man appeared, with a golden axe on his shoulder. He steered the boat to land with the axe, then threw it ashore; a spring appeared where it landed. He taught them laws and then disappeared. The stranger and the spring have traditionally been identified with Fosite and the sacred spring of Fositesland.
Source: Forseti – Wikipedia