Emptyness

Truly Empty
All things are temporary and transient in the Universe. Nothing had a permanent substance, nor an eternal structure. All things arise and perish. The Universe is in a constant state of change and alteration. A Dharma one day may not be a Dharma the next. The Truth is not stagnant nor stationary but keeps up with the laws of Universal change.
The Universe is in flux and constantly flowing and never remains the same in many instances.
2. Truly Nonempty
Since it has been made clear that the essence of all things is empty, i.e., devoid of illusions, the true Mind is eternal, permanent, immutable, pure, and self-sufficient; therefore, it is called “nonempty”. And also there is no trace of particularities to be identified. As it is the sphere that transcends thoughts and is in harmony with enlightenment alone.
The Storehouse Consciousness
The Mind as phenomena (samsara) is grounded on the Tathagata-garbha (Tathagata Matrix). What is called the Storehouse Consciousness is that in which “neither birth nor death (nirvana)” diffuses harmoniously with “birth and death (samsara)”, and yet in which both are neither identical nor different. This Consciousness has two aspects which embrace all states of existence and create all states of existence. They are: (a) the aspect of enlightenment, and (b) the aspect of non-enlightenment.
a. The Aspect of Enlightenment
Original Mind:
The essence of Mind is free. The characteristic of that which is free from thoughts is alike in such a way as to permit the drawing of an analogy to that of the sphere of empty space that pervades everywhere. The one without any second, i.e. the attained aspect of the World of Reality (dharmadhatu) is none other than the undifferentiated Dharmakaya, the “Body of Truth) of the Tathagata. Since the essence of Mind is grounded on the Dharmakaya, it is to be called the original enlightenment. Why? Because “original enlightenment” indicates the essence of Mind (Original Mind) in contradistinction to the essence of Mind in the process of actualization of enlightenment; the process of actualization of enlightenment is none other than the process of integrating the identity with the original enlightenment, Nirvana.