Vidar similed, he and his father played this game before, while he waited in case he is needed. His father would show false trust to the enemy. To see how eager they were to strike.
"Dulce bellum inexpertis."
Official Forum Expert on Norse Mythology
As Odin says in the Hovamal:
"Praise no day 'til evening; no wife 'til on her pyre; no sword 'til tested;
no maid 'til bedded; no ice 'til crossed;
no ale 'til drunk."