Buddha explains Great Nirvana

This is Mahaparinirvana [i.e. Great Nirvana]. "O good man! "Great" means "all-wonderful". All-wonderful is that which all beings cannot believe in. This is "Mahaparinirvana". Being seen only by the Buddha and Bodhisattvas, it is called Great Nirvana. Why do we say "Great Nirvana"? Because one can only attain it through innumerable causal relations. So we say "Great". "O good man! Just as people say "great" when things are gained by the working together of many causal relations, so do things stand with Nirvana. As it can be gained by the conjoint working of many causal relations, we say "Great". "And why do we say "Great Nirvana"? As there is the Great Self, we speak of "Great Nirvana". As Nirvana is selflessness [i.e. non-ego] and Great Sovereignty" "[i.e. great freedom from all restrictions; unlimited autonomy; the ability to do as one wills], we speak of 'the Great Self'. What do we mean by 'Great Sovereignty'? "If there are eight sovereignties, we speak of 'the Self'. "What are these eight? "Firstly, a single body can be manifested as many. The number of bodies is like the number of dust-motes. They fill the innumerable worlds in all directions. The body of the Tathagata is not a mote. [But] due to this sovereignty, it can project a mote-body. Such sovereignty is the 'Great Self'. "Second, we see that a mote-body fills the 3,000 great-thousand worlds. The Tathagata's body does not, in truth, fill the 3,000 great-thousand worlds. Why not? Because of unhinderedness. Due to sovereignty, it fills the 3,000 great-thousand worlds. Such sovereignty is called the 'Great Self'. "Third, with this body that well fills the 3,000 great-thousand worlds, he lightly flies through the air, passing Buddha-lands as innumerable as the number of grains of sand of 20 Ganges, and there is nothing that obstructs him. The body of the Tathagata cannot, truth to tell, be designated as possessing light or heavy weight. [His] sovereignty decides the lightness or heaviness. Such sovereignty is the 'Great Self'. "Fourthly, because of sovereignty, sovereignty is acquired. What is sovereignty? The Tathagata abides [calmly] with one-pointedness of mind, without wavering. [Yet] he is able to manifest countless kinds of forms and endows each of them with a mind. On some occasions, the Tathagata might create a single phenomenon and bring about the needs of each being. Though the Tathagata's body abides in a single land, he causes all those in other lands to behold him. That manner of sovereignty is called the 'Great Self'. "Fifth, he is sovereign over his sense-organs. How is he sovereign over his sense-organs? One sense-organ of the Tathagata can indeed see colours, hear sounds, register smell, know taste, feel touch, and know dharmas. Because of [his] sovereignty, he is sovereign over his sense-organs. Such sovereignty is called the 'Great Self'. "Sixthly, due to [his] sovereignty, [he] acquires all dharmas [all things] and yet there is no concept of attainment in the Tathagata's mind. Why is that? Because there is nothing to be acquired. If there were something [to be acquired], then one could call it 'acquiring', but because there is nothing actually to be acquired, how can it be called 'an acquiring'? If one were to suppose that the Tathagata had the notion of acquiring, then Buddhas would not acquire Nirvana. Since there is [no notion of] acquiring, one can say that they acquire Nirvana. Due to sovereignty, he acquires all dharmas. Because he attains all dharmas, he is called 'the Great Self'. "Seventh, we speak of sovereign. The Tathagata expounds all meaning. And for innumerable kalpas, the meaning has no end, and this meaning is: the moral precepts, samadhi, giving, and Wisdom. At such times, the Tathagata has no sense or thought such as : 'I say', 'they listen'. Also, there is no single thought of a single gatha [verse]. People of the world speak of a gatha made up of four verse lines. This is merely to accord with the way of the world, and we speak of a 'gatha'. The natures of all things also possess nothing of which one can speak. Due to sovereignty, the Tathagata expounds [Dharma]. For this reason, we say 'the Great Self'. "Eighthly, the Tathagata pervades all places, just like space. The nature of space cannot be seen; similarly, the Tathagata cannot really be seen, and yet he causes all to see him through his sovereignty. Such sovereignty is termed 'the Great Self'. That Great Self is termed 'Great Nirvana'. In this sense it is termed 'Great Nirvana'. "Moreover, Noble Son, a treasury, for example, contains many different kinds of rare things and is thus called a great treasury. The extremely profound treasury of the Buddha-Tathagatas is like that: since it contains wondrous [things], without any deficiency, it is termed 'Great Nirvana'. "Moreover, Noble Son, a thing which is unbounded is called 'Great'. Since Nirvana is also unbounded, it is termed 'Great'. "Also, next, O good man! As there is Great Bliss, we say Great Nirvana. Nirvana has no bliss. Because of the four blisses, we say "Great Nirvana". ""What are the four? Firstly, it is segregated from all blisses. If bliss is cut out, we have suffering. If there is suffering, we do not say "Great Bliss". When bliss is cut out, there is no suffering there. What has no suffering and no bliss is Great Bliss. The nature of Nirvana is non- suffering and non-bliss. Thus we say that Nirvana is Great Bliss. For this reason, we speak of Great Nirvana. "Also, next, O good man! There are two kinds of bliss. One is that of the common mortal, and the other that of the Buddhas. The bliss of the common mortal is not eternal - it collapses. Hence, no" "bliss. With all Buddhas, bliss is eternal. There is no change. So we call it Great Bliss. "Also, next, O good man! There are three feelings. One is that of suffering; the second is that of bliss; and the third is of non-suffering and non-bliss. "What obtains in Nirvana is the same as non-suffering and non-bliss. Yet we call it Great Bliss. Because of [this] Great Bliss, we say Great Nirvana. "Second, we say Great Bliss because of the Great Silence. The nature of Nirvana is Great Silence. Why? Because it is removed from all that is noisy. The Great Silence is called Great Nirvana. "Third, we say Great Bliss because of All-Knowledge. If there is not All-Knowledge, we do not say Great Bliss. As the All-Buddha-Tathagata is All-Knowledge, we say Great Bliss. On account of [this] Great Bliss, we say Great Nirvana. "Fourth, we say Great Bliss because the body does not break up. If the body breaks up, we do not say "bliss". The body of the Tathagata is Adamantine and Indestructible. It is not a body of defilement, nor one of the non-eternal. Hence, Great Bliss. Because of Great Bliss we say Great Nirvana.

-The Mahaparinirvana