Exodus 3:12, 18

God answered, “I will be with you. And this is your sign that I am the one who has sent you: When you have brought the people out of Egypt, you will worship God at this very mountain.”

“The elders of Israel will accept your message. Then you and the elders must go to the king of Egypt and tell him, ‘The LORD, the God of the Hebrews, has met with us. So please let us take a three-day journey into the wilderness to offer sacrifices to the LORD, our God.’