Imagine God challenging you to find anything in all of history that compares to what He's done for you. That's exactly what Moses is doing here!
Moses doesn't just ask the Israelites to believe his word; he commands them to seek the evidence.
Search All of Time and Space
He urges them to "ask now of the days that are past, which were before you, since the day that God created man on the earth." This isn't a casual question. It's an invitation to conduct a global, historical investigation.
The Uniqueness of God's Actions
Moses wants them to search "from one end of heaven to the other." This hyperbole emphasizes the boundless scope of their inquiry. He's saying, 'Look everywhere, throughout all of human history, across the entire known world. Has anything ever been seen or heard that rivals what our God has done for us?' The implication is clear: they will find nothing comparable.