Saxo's Answer

4. I. Now although Odin was regarded as chief among the gods, he
would approach seers, soothsayers, and others whom he had dis-
covered strong in the finest arts of prediction, with a view to
prosecuting vengeance for his son. Divinity is not always so perfect
that it can dispense with human aid. Rosthiof the Finn foretold that
Rinda, daughter of the Russian king, must bear him another son, who
was destined to take reprisal for his brother’s killing; the gods had
ordained that their colleague should be avenged by his future
brother’s hand. Acting on this intelligence, Odin muffled his face
beneath a hat so that he would not be betrayed by his appearance and
went to this king to offer his services as a soldier.


- Gesta Danorum, Book III