Birds and flour offering cannot make an exchange, that is, if one says, “Let this bird be a substitute for that bird which is a sacrifice,” his words have no effect whatsoever. The Torah said, “If one does substitute an animal...” – only animals are included in this law, but not birds, and not flour.
Likewise, the community and partners cannot make an exchange with their offering, since the Torah stated, “He shall not exchange.” This tells us that only “he” is included in this law, not community or partners.
Rabbi Shimon says that the derivation is different: animal tithe was included in the laws of exchange, together with all other
animals. When the Torah then repeated this, it is teaching us something new, namely, the exception that “improves” the rule, that is, teaches something about it. Just as tithe can only separated by an individual, so too exchange can only done by an individual. Parenthetically, just as tithe is an Altar offering, so should be animals subject to exchange – which excludes offerings made for Temple maintenance.
Art: John Frederick Herring Snr - Still life of dead birds, fruit, vegetables, a bottle and a jar