We need to produce a document with references to the scattered documentation that exists as to the sayings of Metrodorus. I'm therefore starting this thread with a quote referenced by Adrastus, and I hope at some point one of us will collect these into a single document. Please add other references to this thread to make that goal easier.
“Even at the moment when your son’s body is on the pyre, or your friend breathing his last, will you not suffer your pleasure to cease, rather than tickle your very grief with pleasure? Which is the more honourable—to remove grief from your soul, or to admit pleasure even into the company of grief? Did I say ‘admit’? Nay, I mean ‘chase after,’ and from the hands, too, of grief itself. 28. Metrodorus says: ‘There is a certain pleasure which is related to sadness.’ We Stoics may say that, but you may not. The only Good which you[11] recognize, is pleasure, and the only Evil, pain; and what relationship can there be between a Good and an Evil? But suppose that such a relationship does exist; now, of all times, is it to be rooted out?[12] Shall we examine grief also, and see with what elements of delight and pleasure it is surrounded? 29. Certain remedies, which are beneficial for some parts of the body, cannot be applied to other parts because these are, in a way, revolting and unfit; and that which in certain cases would work to a good purpose without any loss to one’s self-respect, may become unseemly because of the situation of the wound. Are you not, similarly, ashamed to cure sorrow by pleasure? No, this sore spot must be treated in a more drastic way. This is what you (METRODORUS?) should preferably advise: that no sensation of evil can reach one who is dead; for if it can reach him, he is not dead. 30. And I say that nothing can hurt him who is as naught; for if a man can be hurt, he is alive. Do you think him to be badly off because he is no more, or because he still exists as somebody? And yet no torment can come to him from the fact that he is no more—for what feeling can belong to one who does not exist?—nor from the fact that he exists; for he has escaped the greatest disadvantage that death has in it—namely, non-existence.