All Dharmas Are Neither of Natural Nature Nor of Causal Nature

Why does the Śūraṅgama Sūtra say that all dharmas are neither of a self-existing nature nor of a nature arising from causes and conditions, but rather of the nature of the tathāgatagarbha? Because all dharmas are generated and manifested by the tathāgatagarbha; they come from the tathāgatagarbha, not from dharmas of causes and conditions, and therefore they are all of the tathāgatagarbha nature. For example, plants grow by relying on plant seeds, soil, water, temperature, and sunlight, but in reality they are brought forth by the tathāgatagarbha, not born from these material things. Therefore it is said that all dharmas are neither of a nature of causes and conditions nor of a self-existing nature, but rather of the tathāgatagarbha nature.