...I don't remember how many, but I know I've killed many. I've been fighting in battlefields ever since I was 5 or 6. I've even participated in the Denmark army's invasion of England. I used to be a warrior. Do you scorn me, Einar?— Thorfinn
His First Friend (最初の友達 Saisho no Tomodachi?) is the 60th chapter of the Vinland Saga series.
Overview[]
Pater tends to Thorfinn's wounds while Einar watches and tells him what happened. Pater gives them medicine for free, stating it is his duty to take care of them. He offers Thorfinn a shirt to replace his ruined one. Back at work in the forest, remembering Thorfinn's movements when he dodged Snake's attack, Einar asks Thorfinn if he ever fought on a battlefield before. Thorfinn confesses to his past as a warrior. Later that night, Einar is seemingly angry about this revelation, but is taken aback when he sees Thorfinn whimpering in his sleep. He wakes him up and tells him he was having a nightmare again. Thorfinn asks Einar why he wakes him up whenever he has nightmares. Einar explains to him that that's because the two of them are friends. Thorfinn is at first confused by this statement, but eventually says thank you to an embarrassed Einar.
Summary[]

Thorfinn is confused when Pater offers him a shirt
At Pater's house, Pater tends to the wounds Thorfinn got from Fox and Snake, noting they are not serious, aside from the upper ear Fox cut. He comments that they are unlucky for being victims of mercenaries' bad jokes. Einar thinks it was no joking matter, as Thorfinn could have been killed. Pater concludes that the important thing is that two of them are alive. Einar starts to say that they cannot afford medicine, but Pater tells him not to worry about the cost as it is his job to take care of them. Einar thanks him and mentions he should thank Arnheid as well, since she was the one who went to Pater to tell him what happened. As they leave, Pater offers Thorfinn his shirt since his old one is now full of holes. Thorfinn is surprised by the gesture and does not respond, a lack of propriety that irritates Einar, who tells him to say thank you. Pater laughs it off and says he knows Thorfinn is more of a silent type. Despite Pater's recommendation to take the day to rest, Thorfinn leaves for the forest. Einar reminds him that Pater told him to rest, but Thorfinn says his wounds are nothing and continues to walk. Einar decides to follow him.

Thorfinn tells Einar he was a warrior and asks him if he feels contempt towards him now
As Thorfinn cuts down trees, Einar remembers how Thorfinn dodged Snake's attack and realizes Thorfinn is not an ordinary man. He asks him if he ever fought on a battlefield. Thorfinn pauses briefly and says he was. Einar asks Thorfinn if he ever killed someone and Thorfinn responds affirmatively, continuing to work without making eye contact. Einar asks how many people he killed and makes some reluctant guesses, unknowingly all much lower than the true number. Thorfinn asks Einar what purpose that knowledge would serve, since Einar hates wars. He tells Einar that he does not know the number of people he killed, though he killed many. He tells him he was at from the age of six and participated in the Danish army's invasion of England. He asks Einar if he hates him now that he knows he was a warrior. Einar looks conflicted.

Einar tells Thorfinn that the two of them are friends
In the barn later that night, Einar ponders about the day's revelations as Thorfinn sleeps. Remembering how war took everything from him, he angrily approaches Thorfinn with a clenched fist, but is startled by Thorfinn's whimpering. He reminds himself that Thorfinn was not the one who killed his family and wakes him up. Einar tells him that he was having a nightmare and then goes back to his bed to lie down. Thorfinn pensively looks at Einar and asks him why he wakes him up every time he has a nightmare. Einar, realizing that Thorfinn is simply not used to being treated nicely, tells him that he does so because the two of them are friends. Thorfinn asks Einar what he means. Embarrassed, Einar yells at Thorfinn for his cluelessness and tells him he should have just said thank you. After a moment, Thorfinn belatedly thanks a bashful Einar.