"See (r'eih), this day I set before you blessing and curse" begins R'eih: a blessing for following God’s commandments and a curse for failing to do so. It goes on to detail a variety of commandments, including laws of kashrut; treatment of the stranger, the needy, the widow, the orphan, and the Levite; and how to observe Pesach, Shavuot, and Sukkot.
Why start with “see?” The text could have simply read, “This day I set before you a blessing and a curse.” Why is that word “see” needed at all? It seems to function as an opening exclamation point, providing emphasis: sit up, take notice, and pay attention. In the South we might say “Listen up, y’all!”