What does Deuteronomy 26:5 mean?

Then you'll say, 'My ancestor was a wandering Aramean. He went down to Egypt, lived there as a foreigner, and became a great nation, but we were mistreated and oppressed.' Deuteronomy 26:5 - Modern Text Bible

(This is a retelling of Israel's humble beginnings and their suffering in Egypt, reminding them of their roots.)