Illustration Credit: Elad Lifshitz, Dov Abramson Studio

When a person uses God’s name to make a really strong promise to do something (or not to do something), that promise is called a נֶדֶר (neder). Our parashah emphasizes that once you make a neder, you must follow through (Devarim 23:34).

Since a neder is serious business, some people say בְּלִי נֶדֶר (bli neder, without a neder) any time they make a promise or agree to something. This makes it clear that they aren’t committing to a neder-level obligation.

Before Rosh Hashanah, there is a custom to do הַתָּרַת נְדָרִים (hatarat nedarim), a ceremony that cancels out any neder you made during the past year. Kol Nidrei, the prayer recited at the very beginning of Yom Kippur, is also about asking God to let us out of our nedarim.