ויקרא, פרק י״ד, פסוק י״ח

The purification of the afflicted person reaches its peak when the remaining oil is smeared on their head, a final act that seals the atonement process [ביאור שטיינזלץ]. Earlier, oil was applied to specific parts of the body. Having already dedicated their thoughts through the earlobe, their actions through the thumb, and their progress through the toe, the individual now receives oil on the head. This represents an absolute dedication of the person, from the very root of their being, to a life of moral and spiritual purity guided by the laws of the Torah [רש״ר הירש]. The priest takes from whatever oil is left over to perform this symbolic act [חזקוני, ביאור יש״ר, רד״צ הופמן].

A debate exists regarding whether applying this oil is strictly necessary to achieve atonement. One approach maintains that it is essential, and the entire atonement depends on it [מלבי״ם, רד״צ הופמן, בשם ר' עקיבא]. Conversely, another view sees this act as merely completing the remnants of the commandment. Because the oil used here is a leftover of a leftover, there was no absolute guarantee that any would remain [תורה תמימה, מלבי״ם, אילת השחר]. Therefore, if the oil accidentally spills and cannot be applied to the head, the atonement is not held back, as the core forgiveness stems from the guilt offering itself [רמב״ן, תורה תמימה, רד״צ הופמן, בשם ר' יוחנן בן נורי]. Nevertheless, if the oil is present and the priest intentionally avoids applying it, the atonement does not take effect [תורה תמימה]. Furthermore, some point out that only the sin offering has the absolute power to hold back the entire atonement if omitted [אדרת אליהו].

The process concludes with the priest making atonement on behalf of the person before God. The concept of atonement is repeated several times throughout this procedure, corresponding to the different offerings brought. Each offering plays a specific role. The guilt offering, which serves as the basis for the anointing with oil, atones specifically for the social sins, such as gossip, that caused the affliction in the first place. Bringing this offering brings an end to the person's sinful past [רמב״ן, טור הארוך, רד״צ הופמן, רש״ר הירש]. The sin offering then purifies the person from their state of impurity or atones for any sins committed during their painful period of isolation. Lastly, the burnt and grain offerings act as a ransom for the soul, allowing the individual to finally return to their home [רמב״ן, טור הארוך, רד״צ הופמן]. Alternatively, this final mention of atonement can be understood as a comprehensive summary of the entire purification journey, bringing together every step, including the initial sending away of the birds [רמב״ן, טור הארוך].