Plato Phaedo

He [Socrates] walked around, and when he had said his legs were heavy he lay on his back as he had been told to do, and the man who had given him the poison touched his body, and after a while tested his feet and legs, pressed hard upon his foot and asked him if he felt this, and Socrates said no. Then he pressed his calves, and made his way up his body and showed that it was cold and stiff. He felt it himself and said that when the cold reached his heart he would be gone. As his belly was getting cold, Socrates uncovered his head — he had covered it — and said — these were his last words — “Crito, we owe a cock to Asclepius*; make this offering to him and do not forget.” — “It shall be done, “ said Crito, “tell us if there is anything else.” But there was no answer. Shortly afterward Socrates made a movement; the man uncovered him and his eyes were fixed. Seeing this Crito closed his mouth and his eyes.”

 

*Asclepius was the god of healing in ancient Greece