That was the theme of a Yom Kippur sermon I once gave from the pulpit of my synagogue. Naturally my readers will want to know why this D’var Torah begins with Yom Kippur when we are not even in the month of Av, never mind Ellul and Tishri.
The answer is that Yom Kippur begins with a solemn prayer about vows, and this week’s Torah reading sets the scene with its words, “If a person makes a vow to the Lord or takes an oath to bind his soul, he must not break his vow” (Num. 30:3).
Solemn obligations must not be treated lightly. It is better not to make a vow than to make one and not fulfil it (Eccl. 5:4). If you do make a vow and regret having done so, you can be released in the presence of a Beth Din.
Unfortunately there are people who do not realise how serious a promise to God is (naturally promises to human beings are also serious and must be fulfilled; prayers and dayyanim cannot help if you fail to keep your word to another person).
I have had my moments when people sat in my office and insisted they were telling me the truth, thinking they could reinforce their statement by saying, “I swear it on my children’s lives!” Such moments scared me. I’m not certain I was believed when I gently chided the person concerned for needing to bring in a vow, an oath or their children (generally, since these conversations tended to be about the person’s marriage, they did not swear on their wife or husband’s life).
Yom Kippur is the day of rebuke when we tell God how sorry we are for promising grandiloquent things; Parashat Mattot is the moment to remember to use words sparingly and wisely and avoid all over-promising to God and man.