There's been a lot in between, of course. However, especially at this time of year, when it's traditional and beneficial to deepen practice, this text becomes more important.
I can see in a way why I'd been putting this off; on first, as well as second glances, this text is pretty to the point despite its length. This is an important text to be considered and taken in slowly and deliberately, and most importantly shows the Buddhist conception of "emptiness," as its rendered in English does not connote nilhilsm, or a complete void, as these concepts still allow description.
Let's go to the text...
Mahāmati the Bodhisattva-Mahāsattva asks the Buddha, "Tell me, Blessed One, how all things are empty, unborn, non-dual, and have no self-nature, so that I and other Bodhisattva-Mahāsattvas might be awakened in the teaching of emptiness, no-birth, non-duality, and the absence of self-nature, and, quitting the discrimination of being and non-being, quickly realize the highest enlightenment."
And the Buddha replies:
Emptiness, emptiness, indeed! Mahāmati, it is a term whose self-nature is false imagination. Because of one's attachment to false imagination, Mahāmati, we have to talk of emptiness, no-birth, non-duality, and absence of self-nature. In short, then, Mahāmati, there are seven kinds of emptiness: (1) The emptiness of individual marks (lakshaṇa), (2) the emptiness of self-nature (bhāvasvabhāva), (3) the emptiness of no-work (apracarita), (4) the emptiness of work (pracarita), (5) the emptiness of all things in the sense that they are unpredicable (nirabhilāpya) [i.e., cannot be stated or described via predicates], (6) the emptiness in its highest sense of ultimate reality realisable only by noble wisdom, and (7) the emptiness of mutuality (itaretara) which is the seventh.
Mahāmati, what then is the emptiness of individual marks? It is that all things have no [such distinguishing] marks of individuality and generality. In consideration of mutuality and accumulation, [things are thought to be realities], but when they are further investigated and analysed, Mahāmati, they are non-existent, and not predicable with individuality and generality; and because thus no such ideas as self, other, or both, hold good, Mahāmati, the individual marks no longer obtain. So it is said that all things are empty as to their self-marks.
Again, Mahāmati, what is meant by the emptiness of self-nature? Mahāmati, it is that all things in their self-nature are unborn, hence the emptiness of self-nature, and it is therefore said that things are empty in their self-nature.
Again, Mahāmati, what is meant by the emptiness of no-work? It is that the Skandhas are Nirvana itself and there is no work doing in them from the beginning. Therefore, one speaks of the emptiness of no-work.
Again, Mahāmati, what is meant by the emptiness of work? It is that the Skandhas are devoid of an ego and its belongings, and go on functioning when there is a mutual conjunction of cause and action. Thus one speaks of the emptiness of work.
Again, Mahāmati, what is meant by the emptiness of all things in the sense that they are unpredicable? It is that the nature of the false imagination is not expressible, hence the emptiness of all things in the sense of their unpredicability. Thus one speaks of the emptiness of unpredicability.
Again, Mahāmati, what is meant by the emptiness in its highest sense of ultimate reality realisable by noble wisdom? It is that in the attainment of an inner realization by means of noble wisdom there is no trace of habit-energy generated by all the erroneous conceptions [of beginningless past]. Thus one speaks of the highest emptiness of ultimate reality realisable by noble wisdom.
Again, Mahāmati, what is meant by the emptiness of mutual [non-existence]? It is this: when a thing is missing here, one speaks of its being empty there. For instance, Mahāmati, in the lecture-hall of the Mṛigārama there are no elephants, no bulls, no sheep, but as to the Bhikshus I can say that the hall is not devoid of them; it is empty only as far as they [i. e. the animals] are concerned. Further, Mahāmati, it is not that the lecture-hall is devoid of its own characteristics, nor that the Bhikshu is devoid of this Bhikshuhood, nor that in some other places, too, elephants, bulls, and sheep are not to be found. Mahāmati, here one sees all things in their aspect of individuality and generality, but from the point of view of mutuality (itaretara) some things do not exist somewhere. Thus one speaks of the emptiness of mutual [non-existence].
These, Mahāmati, are the seven kinds of emptiness of which mutuality ranks the lowest of all and is to be put away by you.
Again, Mahāmati, not that things are not born, but that they are not born of themselves, except when seen in the state of Samādhi—this is what is meant by "all things are unborn." To have no self-nature is, according to the deeper sense, to be unborn, Mahāmati. That all things are devoid of self-nature means that there is a constant and uninterrupted becoming, a momentary change from one state of existence to another; seeing this, Mahāmati, all things are destitute of self-nature. So one speaks of all things having no self-nature.
Again, Mahāmati, what is meant by non-duality? It means that light and shade, long and short, black and white, are relative terms, Mahāmati, and not independent of each other; as Nirvana and Samsara are, all things are not-two. There is no Nirvana except where is Samsara; there is no Samsara except where is Nirvana; for the condition of existence is not of mutually-exclusive character. Therefore, it is said that all things are non-dual as are Nirvana and Samsara. For this reason, Mahāmati, you should discipline yourself in [the realization of] emptiness, no-birth, non-duality, and no-self-nature.