67:11 The vows that a father or husband can nullify include only those that involve self-deprivation, such as if a woman committed not to wash, wear jewelry, put on make-up, or similar such things. The husband may also nullify vows that do not involve self-deprivation if they do involve matters between the two of them that will lead to marital strife. In the case of annulling vows to avoid marital strife, such vows are only suspended so long as the couple remains together. If they divorce or the wife is widowed, the thing she vowed resumes its prohibited status to her.
68:1 When a person sets out on a journey, whether he is departing from his home or from some place where he was staying during the course of his travels, and also on the return leg of his trip, he says Tefillas HaDerech, the traveler’s prayer. This should be said after he departs the outskirts of the city; which is defined as 72 2/3 cubits from the last house. (A cubit is about 18 inches, so we’re talking about 109 feet.) The plural form, e.g. “lead us to peace,” is used throughout this prayer except for the phrase “grant me grace,” which is in the singular. (After the fact, one has fulfilled his obligation in Tefillas HaDerech even if one recited it while still within the city limits or in the singular – Mishnah Brurah 110:29 and 110:18, respectively.) It is preferable to recite Tefillas HaDerech after traveling a mil (about 2/3 mile) from the city’s outskirts. When a person is already on his way and he stays overnight in a city, he may recite Tefillas HaDerech in the morning before he departs (since he is already underway on his journey – MB 110:29).