The Individual is the Collective

Today you are all standing before God your Lord – your leaders, your tribal chiefs, your elders, your law enforcers, every Israelite man. You are thus being brought into the covenant  of God your Lord, and (accepting) the oath that He is making with you today.      Deuteronomy 29:9,11

Netziv understands our verses to hint at the judgment of Rosh haShana and notes that in addition to standing before God on "this day", for the purpose of entering into His covenant, Israel stands before God annually on Rosh haShana, to be judged.

The emphasis of "koolchem" ("all of you"), explains Netziv, conveys an important point. Certainly, each person is judged by the Almighty as an individual, and is responsible for his deeds. However, each individual's behavior has a powerful impact upon the collective, as our Sages teach us [Babylonian Talmud, Kiddushin 40b]:

One should always see himself as being in balance between merits and sins, and the entire world as well as in balance; therefore, if he commits an additional sin, he has tipped the scale for himself and for the entire world and has caused destruction; should he perform an additional mitzva, he has tipped the scale for himself and the entire world for the good and has brought them and himself salvation.

Thus, verse 9 is addressed in the plural form, while verse 11 is entirely in the singular, to indicate that there is both a personal and a collective responsibility for one's actions. In essence, the individual is the collective and the collective is the individual.