All dharmas are the nature of tathāgatagarbha

Why does the Śūraṅgama Sūtra say that all dharmas are neither of a natural nature nor of a conditioned nature, but rather of the nature of the tathāgatagarbha? Because all dharmas are generated and manifested by the tathāgatagarbha; they are all of the tathāgatagarbha nature, arising from the tathāgatagarbha, not arising from conditioned dharmas. For example, a plant grows by relying on plant seeds, soil, water, temperature, and sunlight. In reality, it is brought forth by the tathāgatagarbha, not born from these material things. Therefore, it is said that all dharmas are not of a conditioned nature but of the tathāgatagarbha nature.