Our Gemara on Amud Beis describes various partitions between two yards and their function. One of them is known as misepas, which can be a barrier, only ten handbreadths high, and a smaller barrier, even less than ten handbreadths. Both small partitions are ineffective in keeping out intruders or line of sight, but the taller one is big enough that a trespasser cannot innocently claim he didn’t realize he was on private property. This has consequences as his unlawful presence automatically puts him in the status of a person with intentions to engage in thievery. In Hebrew, the idiom is nitfas alayv ke-ganav, which loosely translates as, “caught red handed.”

In life there are different kinds of boundaries, and some of them function like this misepas, in a sense that they are more effective as reminders than preventatives. And, amongst those boundaries, some of them function as a means to puncture rationalizations, such as how we blow the cover story of the thief by pointing out the obvious partition that he walked. So too, in life, there are some boundaries whose function is to remind you and catch your rationalizations. The morality of certain actions or behaviors are sometimes judgment calls, and can be innocent or less so. For example, the content and time of day that a text is sent to a married co-worker, or a questionable business deal that one decides their spouse doesn’t need to know about. Technically, there can be good excuses for either behavior. This is why couples should discuss boundaries in advance; it is not merely a matter of proper or improper. Examples of boundaries include: How much one spends without consulting a spouse, what kinds of professional and personal relationships are acceptable with members of the opposite sex, and information that is ok to keep private and what must be shared, and how disclosures are dealt with. Whenever one notices an erosion of agreed upon boundaries, just like the mesipas, it makes it harder to rationalize, acting as an early warning system. It might be innocent, but what internal pressure caused you to violate the standard you agreed to? This shows that something fishy is going on and can allow you to catch yourself before a serious transgression is committed.