Where does “ὑπεῖπον” come from?

ὑπεῖπον (Ancient Greek) comes from Ancient Greek εἶπον, from Proto-Hellenic eweikʷom, from Proto-Hellenic eweukʷom, from Proto-Indo-European wéwket, from Proto-Indo-European wekʷ- — to speak, to sound out.

ὑπεῖπον (Ancient Greek): to say as a foundation or preface, to premise, suggest