Nemea X, 153-171

Pollux, son of Zeus, shared his immortality with his brother Castor, son of Tyndarus, and while one was in heaven, the other remained in the infernal regions, and they alternately lived and died every day, or, as some say, every six months. While Castor lies mortally wounded by Idas, Pollux prays to Zeus, either to restore his brother to life, or permit him to die with him, to which the god answers,--

Nevertheless, I give thee Thy choice of these: if, indeed, fleeing Death and odious age, You wish to dwell on Olympus, With Athene and black-speared Mars, Thou hast this lot; But if thou thinkest to fight For thy brother, and share All things with him, Half the time thou mayest breathe, being beneath the earth, And half in the golden halls of heaven. The god thus having spoken, he did not Entertain a double wish in his mind. And he released first the eye, and then the voice, Of brazen-mitred Castor.