If you notice among the captives a beautiful woman and are attracted to her, you may take her as your wife. Bring her into your home . . . After she has lived in your house and mourned her father and mother for a full month, then you may go to her and be her husband and she shall be your wife. — Deuteronomy 21:11–13

The Torah portion for this week is Ki Teitzei, which means “when you go out,” from Deuteronomy 21:10–25:19, and the Haftorah is from Isaiah 54:1–10.

What would you change about yourself if you could?

Most people have a list of things that they would change if they were given a magic wand. Less angry, more compassionate. More trusting, less anxious. Thinner, stronger, healthier. Yet, for all we’d like to change, there’s very little we do change, not because we can’t, but because we are overwhelmed by what it might take to do so. However, a verse in this week’s Torah reading teaches us that change is not as hard as we think.

This week’s Torah portion contains a whole host of laws. Among the first is a law regarding when a beautiful woman was taken captive in war. The assumption is that the war was fought in accordance with God’s will and that a soldier, in the heat of battle, was drawn to an attractive captive. The law required that the woman be given a full month to mourn the loss of her family before the soldier could take her as a wife.

There are many commentaries on this law and reasons suggested for the 30-day waiting period. One suggests that after 30 days the soldier might realize that he didn’t love the woman after all and that he was just caught up in the moment. Another suggestion is that crying calms the nerves, and after a month of crying, the woman had fully grieved for the losses she sustained in war and was able to move on. A third approach — and the one I would like to focus on — states that it takes 30 days to change a habit, and so the captured woman needed 30 days to purge herself of her idolatrous ways until she could marry into God’s people.

What a useful bit of truth! Thirty days is what it takes to make a change.

This idea, put forth by the Sages thousands of years ago, was the subject of a recent TED talk where the speaker presented the “30-day challenge.” The idea was to encourage people to try something new for 30 days. Thirty days is not too short so that a change is insignificant and fleeting. On the other hand, 30 days isn’t too long so that the goal is actually attainable.

It just so happens that as we read this Torah portion, we find ourselves in the midst of a 30-day time period designated for introspection and growth. The entire month before the High Holy Days is meant for change. It’s the perfect time to pick something about yourself that you’d like to change – drop a bad habit or cultivate a new one – and try it, for just 30 days.

How might you implement the 30-day challenge starting today?