Exodus 5:1-3

MLV(i) 1 And afterward Moses and Aaron came and said to Pharaoh, Jehovah says thus, the God of Israel, Let my people go, that they may hold a feast to me in the wilderness.
2 And Pharaoh said, Who is Jehovah, that I should listen to his voice to let Israel go? I do not know Jehovah and moreover I will not let Israel go. 3 And they said, The God of the Hebrews has met with us. Please, let us go, three days' journey into the wilderness and sacrifice to Jehovah our God, lest he fall upon us with pestilence, or with the sword.