Hilchos Bikkurim 1:9

The eight gifts that may only be eaten in the Sanctuary are the sacrifices of the highest sanctity. They may only be eaten by male kohanim, as will be discussed IY”H when we get to Hilchos Maaseh Hakorbanos. Regarding these offerings, Leviticus 6:22 says: “All males among the kohanim may eat of it.”

Hilchos Bikkurim 1:10

The five gifts that may only be eaten in Jerusalem are the sacrifices of lesser sanctity. Males and females of kohein families may both eat of them. Concerning these, Numbers 18:11 states: “To you and your sons and your daughters with you I have given them as an eternal portion.” However, these are given specifically to the males of kohein families because they’re given to the kohanim who are “on duty,” who are men. The fat and blood of firstborn animals was offered, specifically by a male. Similarly, the hides of the sacrifices of highest sanctity, ancestral fields, dedicated property and the stolen property of a convert are only acquired by the male kohanim who are “on duty,” as we shall see, IY”H. The money from redeeming firstborn sons also goes to male kohanim because Numbers 3:48 tells us: “You shall give the money to Aaron and his sons.” The sheep used to redeem firstborn donkeys likewise go to male kohanim because the laws of firstborns are all the same. Therefore, the redemption goes to males of kohein families rather than females.