Halakhah for Pesachim 118:4

The commandment of eating the meat of sin-offerings and guilt-offerings: That the priests were commanded to eat the meat of some of the sacrifices - such as the guilt offering and the sin offering, as it is stated about them (Exodus 29:33), "They shall eat that with which atonement was done." And they, may their memory be blessed, said (Pesachim 59b), "The priests eat, and the owners are atoned." And with God's help, we will write about the matter of the procedure of the sin-offering and the guilt-offering, how they would do it, and the time of its eating in their Order (Sefer HaChinukh 138, 140). And the principle of the matter is that all the meat of the sacrifices of the sin-offering and the guilt-offering was eaten by the males of the priesthood in the [Temple] yard, except for their entrails; and the owners do not have any [part] in it. And there it will also be explained what are the parts that are to be burned. And also included in this positive commandment is that they eat the portion that is coming to them from the group of sacrifices called lightly consecrated. And the eating of the priestly tithe is also included in the commandment. However, the eating of the lightly consecrated, and so [too,] the priestly tithe, is not like the eating of the meat of a sin-offering and a guilt offering. As with the eating of a sin-offering and a guilt-offering, the atonement of the penitent is accomplished - as they, may their memory be blessed, said, "The priests eat, and the owners are atoned." But the eating of the lightly consecrated and the priestly tithe does not add or subtract from the commandment of the one who brings [the sacrifice] or gives the [tithe].

It is from the roots of the commandment to eat every sacrifice in its place so that its eaters will focus their hearts on the atonement for which they are eating. And it is like the matter that they, may their memory be blessed, said (Pesachim 59b), "The priests eat, and the owners are atoned." And if they ate them in other places, their focus would be dissipated from the matter. This thing is well-known and clear.

It is from the roots of the commandment [that it is] because the consecrated foods are the table of the Higher realm, and it is not fitting for someone who is worried and very hurt in his heart to approach the table of the King. And by way of an analogy, it is like the matter that is written, "for one should not enter the gate of the king with sackcloth" (Esther 4:2). And another reason is because atonement of the owner is found in the eating of the consecrated foods - and like the matter that they, may their memory be blessed, said (Pesachim 59b), "The priests eat, and the owners are atoned." And there is no doubt that when they would eat their consecrated foods, they would eat them with great concentration and with complete minds and [that] all of their thoughts and movements would be proper in front of God. And in a person being distressed, worried and trembling on the day of his relatives's death, his mind and concentration will not be settled at all. And therefore, it is not fit to eat the consecrated foods of the Heavens [at that time]. And the matter is fit in the eyes of the one who says it (the author).