We have learned that the kohanim and levi’im were divided into 24 mishmarot – groups that served in the Beit HaMikdash two weeks out of every year. The first Mishna in the fourth perek of Massekhet Ta’anit introduces us to the concept of ma’amadot – 24 groups of Israelites (i.e. Jews who are neither kohanim nor levi’im) who were assigned to spend two weeks out of the year involved in prayer and study in community synagogues. It should be noted that, according to the Rambam, while all kohanim were obligated to serve in the Beit HaMikdash as members of their mishmar, the ma’amadot were not for all community members, but only for the uniquely pious individuals who volunteered for this responsibility.
The Mishna explains that the source for creating ma’amadot stems from the passage in Bamidbar (28:2) in which the Jewish people are commanded to bring a daily sacrifice – the korban tamid. The Mishna argues that when any sacrifice is brought to the Temple, its owner stands at its side. Who stands by the side of communal sacrifices? The early prophets established the system of ma’amadot to serve that purpose.
The point is raised that the Mishna takes for granted that every sacrifice needs its owner to accompany it. Although this is clearly true for korbanot that require semikha (laying hand on the sacrificial animal), why is this essential for other sacrifices? The Iyun Ya’akov suggests that this idea is connected with the position of many commentaries, who explain the purpose of animal sacrifice as an attempt to engage the individual who brings the korban in some level of soul-searching. The process that the animal goes through in preparation for sacrifice – slaughter, having its skin removed, being disemboweled, etc. – should inspire the person to think “really, I deserve to have these actions done to me; it is God’s mercy that allows them to be carried out on this animal in my stead.” If this is true, we can easily understand why it is important to have the person bringing the korban present when it is being sacrificed.