The "churning of the ocean" refers to a significant event in Hindu mythology known as the Samudra Manthan. It describes the process where gods and demons worked together to churn the cosmic ocean to obtain valuable treasures, including the elixir of immortality. This event involved using the giant serpent Vasuki as a rope and the Mount Mandara as a churning rod. As they churned, various precious items and beings emerged from the ocean, symbolizing the duality of good and evil in the world.