You need the actual game files. The most reputable source is the (archive.org) or the Minecraft Wiki ’s version archive.

Minecraft's journey began in May 2009, when Notch, a self-taught game developer, started working on the game as a side project. Inspired by games such as Dwarf Fortress, Dungeons & Dragons, and Infiniminer, Notch aimed to create a game that allowed players to build and explore a procedurally generated world. The first version of Minecraft, an internal build, was created in just a few weeks. Notch shared the game with a few friends, and the feedback was overwhelmingly positive.