Peace offerings brought as a vow or a freewill donation reflect a state of routine tranquility, standing in stark contrast to the thanksgiving offering. The primary approach among commentators is that while a thanksgiving offering is brought in gratitude for salvation from distress, requires accompanying loaves of bread, and must be consumed within a single day, vow and freewill offerings carry no bread requirement and are granted an extended consumption period of two days and one night. This expanded timeframe also applies to the Passover sacrifice and the joyful offerings brought during the festivals [תורה תמימה, מלבי״ם, פרדס יוסף].
A distinct legal and conceptual difference exists between a vow and a freewill offering. A vow is a personal obligation, often undertaken during times of worry or distress, where an individual commits to bringing an offering. Because the responsibility rests entirely on the person, they must replace the designated animal if it dies or becomes disqualified before being sacrificed. Conversely, a freewill offering is volunteered out of a generous spirit, dedicating a specific animal for the altar. In this case, the sanctity applies only to that exact animal; if it dies, the individual's obligation expires without any requirement for replacement [אבן עזרא, חזקוני, רשב״ם, שד״ל, רש״ר הירש]. Because of this dynamic, a vow can sometimes be viewed in a negative light as an initially undesirable action, whereas a freewill offering is considered a superior and more proper path of worship [העמק דבר].
Regarding the timeframe for eating the meat, a distinction is drawn between the ideal practice and the acceptable reality. The optimal fulfillment of the commandment is to consume the meat on the very day it is offered, though it remains entirely permissible to continue eating it on the following day [רמב״ן, רלב״ג, ביאור יש״ר]. The actual procedures of the sacrifice, such as slaughtering the animal and sprinkling its blood, must be performed exclusively during daylight hours [תורה תמימה, רש״ר הירש].
A fascinating discussion emerges regarding the phrasing used to permit eating the remaining meat on the second day. One approach suggests that the specific wording is merely a common stylistic feature of biblical syntax, simply stating that whatever is left over may be eaten the next day [רש״י, טור, שפתי חכמים]. However, other commentators find precise legal meaning in the text's structure, arguing that it serves to emphasize that there is no religious duty to intentionally divide the meal across two days. The allowance to eat on the second day applies primarily to meat that coincidentally remained. Nevertheless, if a person deliberately sets aside all the meat for the second day, it is not disqualified and remains fully permitted for consumption [רמב״ן, גור אריה, נתינה לגר].
Beyond these two permitted days, strict boundaries govern the lifespan of the offering. The meat may be eaten throughout the day of the sacrifice, the ensuing night, and the entire second day. The moment night falls after the second day, marking the beginning of the third day, the meat becomes strictly forbidden. Although it is now prohibited for consumption, it cannot be destroyed immediately in the dark, as the burning of holy items must take place during the day. Therefore, the meat is held in waiting until the dawn of the third day, at which point it is finally burned in the fire [מזרחי, דברי דוד, פירושי רד״צ הופמן].
Finally, the sacrificial service demands absolute purity of thought. If the officiating priest harbors the intention to eat the meat on the third day while he is slaughtering the animal or sprinkling its blood, the offering is immediately disqualified and classified as an abomination. However, if the service was performed flawlessly with appropriate intentions, and a person later commits the severe transgression of eating the meat on the third day, the sinful act does not retroactively invalidate the original sacrifice [מזרחי, צפנת פענח].