The Iliad 14.269–270

So spake she, and Sleep waxed glad, and made answer saying: Come now, swear to me by the inviolable water of Styx, and with one hand lay thou hold of the bounteous earth, and with the other of the shimmering sea, that one and all they may be witnesses betwixt us twain, even the gods that are below with Cronos,that verily thou wilt give me one of the youthful Graces, even Pasithea, that myself I long for all my days. So spake he, and the goddess, white-armed Hera, failed not to hearken, but sware as he bade, and invoked by name all the gods below Tartarus, that are called Titans.