Talking Parsha - Ki Teitze: Did you have to say that?

This week's Torah portion tells us not to be late in fulfilling a vow & says that a person who did not vow, did not sin. Why would we even think that not making a vow would be a sin?

Tuvia and Yitzi ,

Talking Parsha
Talking Parsha
Tuvia and Yitzi

This week we read about the mitzvah (commandments) of not being late in fulfilling a neder (a vow) a person takes upon himself to bring a korban (sacrifice) in the Mikdash (Holy Temple).

Why does the Torah emphasize the time aspect? Why doesn't the Torah just say, "Make sure to fulfill your neder?" The Torah then continues to say, that if a person doesn't pay on time, it's a sin, and if a person doesn't vow at all - then there's no sin.

Why does the Torah have to tell us that someone who didn't vow, didn't sin? Why would we even think of that as a sin?