Then the Levites shall declare in a loud voice to all the Israelites . . . “Cursed be anyone who moves a neighbor’s boundary marker.” All the people shall say, “Amen!” (Deut 27:14, 17)
Before a person testifies in court, they “solemnly swear to tell the truth, the whole truth and nothing but the truth.” (I have never attended an actual trial, but I know this because I’ve seen dozens of courtroom movies.) Something like this solemn swearing happens in our parsha, where the people answer “amen” to 12 curses pronounced by the Levites. “Amen” is derived from a root meaning “firm”; the ancient Greek translation renders “amen” as “let it be so.” By responding “amen” one endorses the wish that the punishment befall whoever commits the sin, even oneself.
Even if you don’t believe that God is going to strike down those who swear falsely, these oaths are effective on two levels. There is the ceremonial level, where community values are upheld and seep into the individual’s consciousness. And then there is the psychological level. The person who says “amen” or “I do” involves herself in the statement. She doesn’t just stand there, a spectator to the Levitical pronouncement; she does something, comes down off the bleachers and joins the team. Of course, she could still commit the proscribed act, but for most people such rituals creates a greater psychological resistance to doing so. A person who, say, removed his neighbors landmark, would fall under his own imprecation, and add the sin of hypocrisy to the sin of theft.