This was said by the Blessed One, said by the Arahant, so I have heard:
“Bhikkhus, this body is fragile; |consciousness::quality of awareness — subjective awareness of experiences and the knowing of objects through the six sense doors [sight, sound, smell, taste, touch, and mind] [viññāṇa]| is of a fading nature. All substrates of |existence::attachments, assets [upadhi]| are |impermanent::not lasting, transient, unreliable [anicca]|, |dissatisfactory::uncomfortable, unpleasant [dukkha]|, and |subject to change::of the nature of alteration, decay [vipariṇāmadhamma]|.”
The Blessed One spoke on this matter. In this regard, it is said:
“Having known the body as fragile,
and consciousness as of a fading nature;
Having seen the danger in substrates [of existence],
one overcomes birth and death;
Having attained the supreme peace,
the Awakened One calmly awaits his time [until final passing].”
This matter too was spoken by the Blessed One, as I have heard.