Kinim, Chapter One, Mishnah One
The first mishnah of our tractate deals with a few general rules regarding bird and other sacrifices.
1) A bird hatat is performed below [the red line], but a beast hatat is performed above [the red line].
a) A bird olah is performed above, but a beast olah below.
b) If he changed this procedure with either, then the offering is disqualified.
2) The seder [ordered ritual] in the case of kinnim is as follows:
a) In the case of obligatory offerings, one [bird] is a hatat and one an olah.
b) In the case of vows and freewill offerings, however, all are olot.
3) What constitutes a vow? When one says: “It is incumbent upon me to bring an olah.”
a) And what constitutes a freewill-offering? When one says: “Behold, this shall be an olah.”
b) What is the [practical] difference between vows and freewill offerings?
i) In the case of vows, if they die or are stolen, one is responsible for their replacement;
ii) But in the case of freewill offerings, if they die or are stolen, one is not responsible for their replacement.
Section one: There was a red line that ran through the middle of the altar. The blood of the bird hatat was sprinkled below this line, whereas the beast hatat (cow, sheep or goat) is sprinkled above the altar, on the corners of the altar. The opposite is true of the olahthe bird olah is done above and the beast olah is done below. These rules must be followed precisely and if they are not, the sacrifice is invalid.
Section two: As I explained in the introduction, when one brings a ken (a pair of birds) as a mandatory sacrifice, one bird is an olah and one is a hatat. However, if one voluntarily dedicates a ken, both birds are olot.
Section three: The mishnah now explains the difference between a vow offering (a neder) and a freewill offering (a nedavah). A neder is when one promises to bring a certain type of offering, either an olah or a shelamim (wellbeing offering). For example if he promises to bring a bird olah, he must bring two birds as an olah. If he sets aside a bird and it is lost or stolen before it can be sacrificed, he must bring a replacement. The case of the nedavah is different. In this case, one points at an animal and promises to bring that animal as a sacrifice. For instance, he points at a sheep and promises to bring it. If the sheep is lost or dies, he is not responsible for its replacement because he was only responsible to bring that sheep as long as it was alive or available.
Note that this last section is not connected specifically to our tractate which deals with bird sacrifices. Rather it is a general rule with regard to voluntary sacrifices.