Rashi on Deuteronomy 27:9/רש"י על דברים כ״ז:ט׳

1הסכת — Understand this as the Targum does: אצית listen!

2היום הזה נהיית לעם THIS DAY YOU HAVE BECOME THE PEOPLE [OF THE LORD YOUR GOD] — On each day it should appear to you as though it were “today” that you have entered the covenant with him (Berachot 63b).