"Now I am frail, Ananda, old, aged, far gone in years. This is my eightieth year, and my life is spent. Even as an old cart, Ananda, is held together with much difficulty, so the body of the Tathagata is kept going only with supports. It is, Ananda, only when the Tathagata, disregarding external objects, with the cessation of certain feelings, attains to and abides in the signless concentration of mind, that his body is more comfortable.
...
And the Blessed One addressed the bhikkhus, saying: "Behold now, bhikkhus, I exhort you: All compounded things are subject to vanish. Strive with earnestness!"
This was the last word of the Tathagata.
How the Blessed One Passed into Nibbana:
And the Blessed One entered the first jhana. Rising from the first jhana, he entered the second jhana. Rising from the second jhana, he entered the third jhana. Rising from the third jhana, he entered the fourth jhana. And rising out of the fourth jhana, he entered the sphere of infinite space. Rising from the attainment of the sphere of infinite space, he entered the sphere of infinite consciousness. Rising from the attainment of the sphere of infinite consciousness, he entered the sphere of nothingness. Rising from the attainment of the sphere of nothingness, he entered the sphere of neither-perception-nor-non-perception. And rising out of the attainment of the sphere of neither-perception-nor-non-perception, he attained to the cessation of perception and feeling.
10. And the Venerable Ananda spoke to the Venerable Anuruddha, saying: "Venerable Anuruddha, the Blessed One has passed away."