The line comes from Warcraft III: Reign of Chaos, the 2002 real-time strategy game by Blizzard Entertainment. The Peasant is the basic Human Alliance worker, used to gather gold and lumber and to construct buildings, and he responds with short acknowledgements each time the player selects or moves him. In the French localisation Oui messire became his signature reply, quoted by French players for years. It later spread through soundboards, streams and short edits, where the old strategy voice line is reused far outside the game.