A Chatos bird is done at the lower part ofthe Mizbayach. A Chatos that is an animal is done at the upperpart of the Mizbayach. An Olah that is a bird is done at theupper part of the Mizbayach. An Olah that is an animal is doneat the lower part of the Mizbayach. If the Kohain changed theplace of the blood in either of these korbonos the korbon isinvalid.
The arrangement of pairs of birds is, that a chova (a pairbrought as an obligation, see the Background section) consists ofa Chatos and an Olah. Kinim that are brought on account ofnedarim and kinim that are contributed as gifts are all Olos.
What is a neder? One who says, "I take upon myself to bring anOlah." What is a nedova? One who says, "This is an Olah." Whatis the difference between nedarim and nedovos? Only in that ifbirds pledged for nedarim died or were stolen the owners arerequired to take responsibility for them. The owner must replacethe lost birds with others. And concerning nedovos, if they diedor were stolen, the owners are not required to take theresponsibility for them.
This is because when the owner says "haray zu," heundertakes to bring these specific birds. If these birds are nolonger available, it is not possible to fulfill his promise. Bysaying "haray olei" he undertakes to bring a korbon. If the birdhe first designates becomes unavailable, he still has theopportunity to -- and, therefore, must -- fulfill his vow withother birds.