Ki Teitzei means “when you go out [to war].” Of the 613 commandments in the Torah, 74 are contained in this Torah portion. A very important command is found concerning promises and vows made to the Lord:
“22When thou shalt vow a vow unto the Lord thy God, thou shalt not be slack to pay it; for the Lord thy God will surely require it of thee; and it will be sin in thee. 23But if thou shalt forbear to vow, it shall be no sin in thee. 24That which is gone out of thy lips thou shalt observe and do; according as thou hast vowed freely unto the Lord thy God, even that which thou hast promised with thy mouth” (JPS 1917, Deut. 23:22–24).
Here we not only find the obligation to honor vows made to God, but also the responsibility to fulfill that vow without delay.