Moses continues to speak to the people of Israel if they were one man, so all instances of "you" and "your" are singular. (See: [[rc://en/ta/man/translate/figs-you]])
Moses speaks as if the people to whom he was speaking were the people he had spoken to at Mount Sinai many years earlier. The people at Mount Sinai were actually the fathers of the people to whom he was speaking these words. AT: "made your fathers ... your fathers heard" (See: [[rc://en/ta/man/translate/figs-metonymy]])