Why Is Sleep Considered a Hindrance?

Consciousness is like a lamp, the mind's nature is like light; when the mind-substance functions, the lamp-light manifests, illuminating all phenomena. During sleep, the five consciousnesses cease, leaving no lamp-light, so the objects of the five senses and six dusts fail to appear. After sleep ends, the five consciousnesses manifest, consciousness manifests, brightness appears, and the lamp-light illuminates the six dusts—this is called being awake. Therefore, sleep is described as darkness, obscuring the innate brightness of the mind. Subduing sleep and eliminating the hindrance of sleep allows meditative concentration to manifest.