The experience of loss naturally brings profound sadness, yet clear boundaries are established for how this grief may be expressed. While priests are permitted to become ritually impure to pay their final respects to close relatives, they are strictly forbidden from taking mourning to an extreme by inflicting physical harm upon themselves. In the ancient world, tearing out hair and slashing the flesh were highly common practices, particularly among idol priests who sought to appease their gods or dramatically display their sorrow [אבן עזרא, הכתב והקבלה, הופמן].
Beyond simply distancing the people from gentile customs, there are fundamental reasons for these restrictions. As servants of God, priests must stand as living symbols of life, rather than bearing the marks of death and despair on their bodies [רש ר הירש]. Furthermore, mutilating oneself out of extreme grief can be interpreted as anger directed toward Heaven and a lack of faith in the eternal survival of the soul, which ultimately desecrates God's name [תולדות יצחק, כלי יקר]. There is also a standard of presentation; a priest serving in the inner sanctuary must be whole and physically dignified. It is entirely inappropriate to stand before God with a bald head, a shaved beard, and a scarred body [אבן עזרא, בעלי ברית אברם].
The primary approach among commentators is that these prohibitions are not exclusive to the priests, but apply to all Israelites. The laws are repeated in the context of the priesthood to teach new details through a system of textual comparisons. Every detail mentioned regarding the priests complements the laws given to the rest of the nation, and vice versa.
For instance, the prohibition against creating a bald spot—whether by physically pulling out hair or applying a hair-removing substance [רש ר הירש]—applies specifically when the act is driven by grief over someone who has died [רש״י, ספורנו, מלבי״ם]. While the laws for the general public mention the area between the eyes, the instructions for the priests clarify that this ban covers the entire head [רש״י, מזרחי]. The repetitive phrasing used to describe the act of making a bald spot indicates that a person is held accountable for each individual spot created. A unique spelling tradition in the Hebrew text even hints at a scenario where a mourning person might tear out five bald spots simultaneously using five fingers; in such a case, the individual incurs a separate penalty for each finger's damage [מנחת שי, מלבי״ם].
A similar comparative deduction is made regarding the beard. The instructions for the Israelites use a term denoting destruction, while the priestly instructions specify shaving. Blending these two concepts reveals that the prohibition specifically targets an action that is both a shave and a complete destruction of the hair from its root. Because this specific type of removal is only achieved using a razor, plucking beard hair with tweezers or using a filing tool does not violate this rule [רש״י, ריב״א, בכור שור].
Finally, the restriction against scratching the flesh encompasses both making a light groove with one's hand and inflicting a deeper wound with a tool [מלבי״ם]. Just as with the laws of baldness, the specific phrasing regarding scratching serves to multiply the accountability. If a person makes several scratches in their flesh, they face a distinct penalty for each individual scratch, even if all the wounds were inflicted at the exact same moment [רש״י, תורה תמימה].