Priests are held to a strict standard of ritual purity to maintain their sacred status, generally forbidding them from coming into contact with the dead. However, a profound exception is made for immediate family members, where the obligation to mourn and bury loved ones overrides these boundaries.
The primary approach among commentators is that the initial reference to a close relative points directly to the priest's wife. This relationship is expressed through the concept of flesh, capturing the deepest physical and spiritual intimacy. A husband and wife are considered one entity, reflecting a bond where she sustains and completes him [כלי יקר, רד צ הופמן, הדר זקנים]. An alternative central approach argues that a priest's obligation to defile himself for his wife is actually a rabbinic decree rather than a strict biblical law. According to this view, because a wife has no other heir obligated to handle her burial, she is treated as an abandoned corpse that anyone must bury, with the scriptural reference serving merely as supporting framework [רמב״ם, מזרחי, רבנו בחיי].
The precise nature of this marital bond is carefully defined to require a fully realized and current relationship. This excludes an engaged woman, as the couple has not yet achieved complete closeness, as well as a divorced woman, who was once close but has since distanced herself [אור החיים, רבנו בחיי, תורה תמימה]. [המלבי״ם] notes that the required intimacy must be active and present, contrasting with a connection belonging only to the past.
When addressing parents, the mother is prioritized over the father. Commentators observe a striking contrast with the laws of the High Priest, who is forbidden from becoming impure for anyone, where the father is prioritized instead. The primary approach among commentators explains this through a progression of emphasis. For a regular priest, who is obligated to bury his parents, the emphasis is that he must defile himself not only for his mother, whose maternity is an absolute certainty, but even for his father, whose paternity relies on natural assumption. Conversely, the High Priest is warned that he must maintain his purity not only from his assumed father, but even from his certain mother [הטור הארוך, רבנו בחיי, דעת זקנים, חזקוני]. Other explanations suggest the mother is prioritized because women historically had shorter lifespans [אבן עזרא, צאינה וראינה], or because she endured greater suffering during childbirth and child-rearing [כלי יקר]. Furthermore, the physical degradation of a woman's body in death is considered more severe; thus, if both parents require burial simultaneously, the mother takes precedence [כלי יקר]. The priest must attend to his mother even if she lost her priestly status, and to his father based on assumed paternity, provided the father's body is whole and not missing a limb [תורה תמימה, צפנת פענח].
Regarding children, the obligation applies exclusively to viable offspring, excluding infants who did not survive for thirty days [אור החיים, תורה תמימה, חזקוני]. The priest must bury his children even if their lineage is flawed, provided they are legally considered his offspring, which excludes children born to a maidservant or a non-Jewish woman [תורה תמימה]. Similarly, the obligation toward a brother applies specifically to a paternal brother, who is in the line of inheritance, rather than a maternal brother [חזקוני, רלב״ג, דעת זקנים]. This duty remains intact whether the brother is of valid priestly status or has been disqualified [תורה תמימה].
Attending to these closest relatives is not an option but an absolute Commandment. This duty is so severe that the sages once physically compelled a priest named Yosef to defile himself for his deceased wife when he refused to do so on the eve of Passover [אור החיים, רבנו בחיי]. Nevertheless, this permission is strictly limited to the actual needs of the burial or being present in the same structure as the deceased. A priest remains strictly forbidden from casually entering a cemetery or walking among graves without a direct, immediate need related to burying his relative [רבנו בחיי, צאינה וראינה].