Lü Dongbin's Secret of the Golden Flower introduces a Daoist internal alchemy practice focusing on "returning the light" to the "heart of heaven," located between the eyes. This involves cultivating one's innate nature (xing) and primordial spirit (yuan shen) to achieve enlightenment, bypassing typical active methods. The text emphasizes the importance of a firm ethical foundation before undertaking this practice, which aims to solidify the light into a natural dharma body, ultimately achieving ascension. The "Golden Flower," representing this light and primordial energy, symbolizes the Golden Elixir, with its manifestation varying according to individual practitioners' minds. The text highlights the necessity of both intelligence and serenity for successful practice.