ויקרא, פרק י״ד, פסוק כ״א

A person seeking purification from their affliction is granted a profound financial leniency if they lack the means to afford the standard sacrifices. While a wealthy individual is required to bring three sheep and three measures of fine flour, an impoverished person may bring just one sheep and one measure of flour, supplementing the remainder of the offering with birds. The exact nature of this poverty is carefully defined to avoid ambiguity. Describing someone merely as poor could imply physical weakness, a drop in social standing, or a formerly wealthy individual who has lost assets but is not truly destitute. Therefore, an additional clarification emphasizes an absolute financial inability to purchase the standard offering. Conversely, without explicitly specifying poverty, one might assume the leniency applies to a wealthy person who simply cannot locate animals at that moment, such as during a siege. Together, these conditions establish that the exemption is strictly due to genuine financial hardship [אור החיים, מלבי״ם, חיזקוני, פרדס יוסף].

The assessment of this financial status is based entirely on the individual's situation at the exact moment the offering is brought. Because the person is eager to complete the purification process immediately, they do not wait for a major pilgrimage festival, making their present economic reality the sole deciding factor [העמק דבר]. Furthermore, this status is evaluated exclusively according to the individual undergoing purification. Even if a wealthy person volunteers to finance the sacrifice for an impoverished friend, the required offering remains that of a poor person, as the individual needing purification is financially destitute [תורה תמימה, מלבי״ם, אדרת אליהו].

Despite these significant leniencies, the core of the purification process requires a sheep for a guilt offering, which cannot be substituted with birds. Because the impoverished individual replaces the other required sheep, namely the sin and burnt offerings, with birds, one might mistakenly assume the guilt offering could also be replaced, or substituted with two birds. To prevent this error, it is established that exactly one sheep must be brought [תורה תמימה, מלבי״ם]. This specific sheep is designated to be waved as part of the atonement process. This presents a conceptual challenge, as atonement is fundamentally achieved through the sprinkling of blood, not through the act of waving. However, this requirement explains why the guilt offering cannot be replaced by a bird, as live birds are not subject to the waving ritual. While omitting the waving does not invalidate the essential atonement achieved by the blood, performing it ensures the atonement is accomplished in the most complete and optimal manner [תורה תמימה, מלבי״ם, ביאור יש״ר].

The single measure of fine flour brought by the impoverished individual is directly tied to their single sheep. It serves as the accompanying libation for that specific animal rather than functioning as an independent meal offering [רש״י, גור אריה, ברכת אשר]. This specific requirement also establishes a broader legal principle that every measure of fine flour brought for a meal offering must be mixed with a full standard measure of oil [תורה תמימה, מלבי״ם]. Finally, an explicit requirement is made for a full measure of oil to prevent a logical misunderstanding. Since the impoverished person brings only a third of the required animals and a third of the flour compared to a wealthy person, one might assume the oil should similarly be reduced to a third. Therefore, it is clarified that a full measure of oil remains mandatory [תורה תמימה, מלבי״ם, רד״צ הופמן]. This oil is primarily used for the purification ritual itself, to be placed on the individual's earlobe, thumb, and toe. The oil needed to mix the meal offering does not need to be detailed here, as its required amount is already established by the general laws of libations [רש״י, שפתי חכמים].