Moses speaks to the people about vows made and how they are binding or not binding. If a man makes a vow to the Lord or binds himself by an agreement of any kind, then he is bound to keep his word. Women are bound only if the men in their lives allow it. If the husband of a wife or the father of a daughter nullifies the vow on the day it is made, then it is not binding. The widow or divorced woman will be bound by her vows, because she has no man to overrule them.
These provisions were for the protection of the weaker gender in society, and demonstrated the covering of women by the authority in their lives. While cultural norms would not support this system today for wives, it still does support the right of parents to cover or protect minors in contractual agreements. The principle, though, still applies Biblically. It is a husband or a father’s right and responsibility to cover or protect his wife or children. Oversight of his family is the patriarch’s duty.
The Israelites commited idolatry and intermarried with the Moabites and the Midianites, and were corrupted by their presence. God instructed Moses to take a band of 12,000 soldiers and attack Midian to exact revenge just before he died. He did just as the Lord commanded, and the Midianites were destroyed and their goods were plundered.
When you are getting ready to enter into the plan of God, or are entering a journey with God to a place of promise, you need to lay aside, even destroy, all the vestiges of sin and past idolatries. It is so extremely important to cleanse one’s self of the things of the world in order to follow God wholly. It reminds me of the Scripture in the New Testament, “lay aside every weight, and the sin which so easily ensnares us. (Hebrews 12:1)” God is looking for unencumbered servants for His servants.