The Dhammapada:
The Buddha's Path of Wisdom
Chapter 11, Verses 146-156
Old Age
146. How is there laughter, how is there joy, as this world is always burning? Why do you not seek a light, ye who are surrounded by darkness?
147. Look at this dressed-up lump, covered with wounds, joined together, sickly, full of many thoughts, which has no strength, no hold!
148. This body is wasted, full of sickness, and frail; this heap of corruption breaks to pieces, life indeed ends in death.
149. Those white bones, like gourds thrown away in the autumn, what pleasure is there in looking at them?
150. After a stronghold has been made of the bones, it is covered with flesh and blood, and there dwell in it old age and death, pride and deceit.
151. The brilliant chariots of kings are destroyed, the body also approaches destruction, but the virtue of good people never approaches destruction,--thus do the good say to the good.
152. A man who has learnt little, grows old like an ox; his flesh grows, but his knowledge does not grow.
153, 154. Looking for the maker of this tabernacle, I shall have to run through a course of many births, so long as I do not find (him); and painful is birth again and again. But now, maker of the tabernacle, thou hast been seen; thou shalt not make up this tabernacle again. All thy rafters are broken, thy ridge-pole is sundered; the mind, approaching the Eternal (visankhara, nirvana), has attained to the extinction of all desires.
155. Men who have not observed proper discipline, and have not gained treasure in their youth, perish like old herons in a lake without fish.
156. Men who have not observed proper discipline, and have not gained treasure in their youth, lie, like broken bows, sighing after the past.