Son of Buddha wrote:
its quite common in the suttas for the Bhagavan Buddha to say he has ended death,rebirth and in turn gives the deathless/immortal.
I found this in the Suzuki translation of the Lankavatara Sutra:
At that time again, Mahamati the Bodhisattva-Mahasattva said this to the Blessed One: Is the Blessed One, the Tathagata, the Arhat, the Fully-Enlightened One, permanent or impermanent? http://lirs.ru/do/lanka_eng/lanka-nondiacritical.htm
Said the Blessed One: Mahamati, the Tathagata is neither permanent nor impermanent. Why? Because either way there is a fault connected with it. Mahamati, what fault is connected with either assertion?1 If the Tathagata is permanent, he will be connected with the creating agencies. For, Mahamati, according to all the philosophers the creating agencies are something uncreated and permanent. But the Tathagata is not permanent [in the same sense] as the uncreated are permanent. If he is impermanent, he will be connected with things created. Because the Skandhas which are predicable as qualified and qualifying are nonexistent, and because the Skandhas are subject to annihilation, destructibility is their nature. Mahamati, all that is created is impermanent as is a jug, a garment, straw, a piece of wood, a brick, etc., which are all connected with impermanency. Thus all the preparations for the knowledge of the All-Knowing One will become useless as they are things created. On account of no distinction being made, the Tathagata, indeed, would be something created. For this reason, the Tathagata is neither permanent nor impermanent.
1 Following T'ang.
Again, Mahamati, the Tathagata is not permanent for the reason that [if he were] he would be like space, and the preparations one makes for Tathagatahood would be useless. That is to say, Mahamati, space is neither permanent nor impermanent as it excludes [the idea of] permanence and impermanence, (218) and it is improper to speak of it as characterised with the faults of oneness and otherness, of bothness and not-bothness, of permanence and impermanence. Further, Mahamati, it is like the horns of a hare, or a horse, or an ass, or a camel, or a frog, or a snake, or a fly, or a fish; [with the Tathagata] as with them here is the permanency of no-birth. Because of this fault of the permanency of no-birth, the Tathagata cannot be permanent.
However, Mahamati, there is another sense in which the Tathagata can be said to be permanent. How? Because the knowledge arising from the attainment of enlightenment [ = an intuitive understanding] is of a permanent nature, the Tathagata is permanent. Mahamati, this knowledge, as it is attained intuitively by the Tathagatas, Arhats, Fully-Enlightened Ones, is, indeed, permanent. Whether the Tathagatas are born or not, this Dharmata, which is the regulative and sustaining principle to be discoverable in the enlightenment of all the Sravakas, Pratyekabuddhas, and philosophers, abides, and this sustaining principle of existence is not like the emptiness of space, which, however, is not understood by the ignorant and simple-minded. Mahamati, this knowledge of enlightenment belonging to the Tathagatas comes forth from transcendental knowledge (prajnajnana); Mahamati, the Tathagatas, Arhats, Fully-Enlightened Ones do not come forth from the habit-energy of ignorance which is concerned with the Citta, Manas, and Manovijnana, and the Skandhas, Dhatus, and Ayatanas. The triple world originates from the discriminating of unrealities, but the Tathagatas do not originate from the discriminating of unrealities. Where duality obtains, Mahamati, there is permanency and impermanency because of its not being one. Mahamati, [the truth of] absolute solitude is, indeed, non-dualistic1 because all things are characterised with non-duality and no-birth. For this reason, Mahamati, the Tathagatas, Arhats, Fully-Enlightened Ones are neither permanent nor impermanent. Mahamati, as long as there is word-discrimination, (219) there follows the faulty notion of permanency and impermanency. The destruction of the notion of permanency and impermanency as held by the ignorant, Mahamati, comes from the getting rid of the knowledge that is based on discrimination, and not from the getting rid of the knowledge that is based on the insight of solitude. So it is said:
1. By keeping away permanency and impermanency, [and yet] by keeping permanency and impermanency in sight, those who always see the Buddhas will not expose themselves to the power of the philosophical doctrines.
2. When permanency and impermanency are adhered to all the accumulation [one makes for the attainment of reality] will be of no avail; by destroying the knowledge that is based on discrimination, [the idea of] permanency and impermanency is kept back.
3. As soon as an assertion is made, all is in confusion; when it is understood that there is nothing in the world but what is seen of the Mind itself, disputes never arise.
Here Ends the Fifth Chapter, "On the Deduction of the Permanency and Impermanency of Tathagatahood."