To understand the purpose of Ki Tetze, one has to think about it as a puzzle. When one examines the different commandments on a deeper level, the mitzvot begin to exemplify a common thread that intertwines each of the commandments with one another. This common unifying thread is relationships and forbidden unions. When one understands this theme, the portion begins to take on new meaning. What is the purpose of these seemingly unrelated mitzvot? The purpose is to instruct us in the proper and improper way to conduct ourselves with others.

Ki Tetze begins with mitzvot concerning the relationship of an Israelite man who wishes to marry a captive woman. It goes on to mention the instructions for a wayward son, and the obligation to extend goodness toward a fellow person: “You are not to watch your brother’s ox or sheep straying and behave as if you hadn’t seen it (Deut. 22:1).” Additionally, “If you find something they lost, you must not ignore it (22:3).”

The entire portion discusses rules of unions, and serves as a reminder of the importance of making sure a relationship is not “mixed,” or impure. As such, there are mitzvot that also serve as reminders to avoid impure relationships and unions. These are the laws of shatnetz, the mixing of species and threads (22:6-11), and the wearing of tzitzit (22:12), which serve as a reminder to observe all the mitzvot.

The remainder of the portion continues with instructions regarding relationships, and who can and cannot enter into the assembly of Israel. These commandments are meant to keep the community of Israel's relationship with HaShem pure. Ki Tetze also deals with the mitzvot concerning those who have violated the instructions regarding relationships (punishments), or to clarify what to do to end a phase of a relationship, as exemplified by the laws concerning the giving of a get, a written document of divorce (24:1-4).

The point of Ki Tetze is relationships, and specifically how to conduct ourselves in relation to one another. This is the essence of holiness. For G-d takes this matter seriously. The Torah repeatedly instructs us on our relationships – both with G-d, and to others.

May we, with G-d’s help, merit that level of unity with each other and with our Creator. “Barcheinu Avinu, kulano k’echad - Bless us, our Father, all of us as one.”