Once upon a time, when Vikings roamed the earth, a bard named Eilífr Goðrúnarson decided to write a drápa, or praise-poem, in honor of Thor. For his story, he chose Thor's encounter with a frost-giant named Geirrod. To really amp up the praise, he filled his poem with twisty-turny titles for the god. He wasn't content with just "Thunder God." Nope, in Eilífr's hands, Thor became "feller of the life-net of the gods of the flight-ledges" and "the maiden-betrayer of the halls of the shrill-crier" (Þórsdrápa 1.3-1.4, 3.6-3.7).
Huh? Yeah, it's a pretty impossible poem to understand.
Even though we have some trouble with it these days, lots of medieval Icelanders loved it. So a few hundred years later (around 1220), Snorri Sturluson decided to include the story in his Skáldskaparmal, a collection of poetry and poetic terms. Thanks to him, even ordinary folks know what happened when Thor visited Geirrod's hall.
Even if we didn't know that Thor and the Jotun Geirrod was a Viking legend, we'd be able to guess. A bunch of the stuff that happens in this story lines up perfectly with what we know about the values of medieval Germanic warrior culture.
Examples? Of course.
(1) Your word is your bond. Even after he's totally free of Geirrod's clutches, Loki keeps his oath to the giant to lure Thor to his hall without his weapons. Oaths are super-important to a Germanic warrior. You don't break them—ever. If you're going to break it, don't make it. Period.
(2) Hospitality. Grid doesn't just give Thor and Loki a hot meal and a soft bed. She also provides Thor with the dirt on Geirrod and the equipment he needs to defeat him. Now that's hospitality. And that's a medieval Germanic warrior's obligation to his guest. When you agree to host somebody under your roof, it's your responsibility to entertain, but also to protect them. Don't feel like going to battle for your guest? Don't ask them to stay.
(3) The sneaky don't prosper. Everyone in this story who tries to use violence in a sneaky way—for example, by hiding under Thor's chair or inviting him to play a game of catch that's actually a game of fireball—dies. A Germanic warrior isn't supposed to use deception to defeat his enemies. It's okay to be violent, but do it straightforwardly, like Thor does.