All Dharmas Are the Nature of Tathagatagarbha

Why does the Śūraṅgama Sūtra state that all phenomena are neither spontaneously arisen nor conditioned, but are of the Tathāgatagarbha nature? It is because all phenomena are born from and manifested by the Tathāgatagarbha; they are all of the Tathāgatagarbha nature, originating from the Tathāgatagarbha, not from conditioned causes. For example, plants grow by means of seeds, soil, water, temperature, and sunlight. In reality, they are born from the Tathāgatagarbha, not produced by these material factors. Thus it is said that all phenomena are not conditioned but are of the Tathāgatagarbha nature.