Translation:Mishnah/Seder Moed/Tractate Yoma/Chapter 6/1

Hebrew Text
שני שעירי יום הכפורים, מצותן שיהיו שניהן שוין במראה ובקומה ובדמים ובלקיחתן כאחד. ואף על פי שאינן שוין, כשרין. לקח אחד היום ואחד למחר, כשרין. מת אחד מהן, אם עד שלא הגריל מת, יקח זוג לשני. ואם משהגריל מת, יביא זוג אחר ויגריל עליהם בתחלה, ויאמר, אם של שם מת, זה שעלה עליו הגורל לשם יתקים תחתיו. ואם של עזאזל מת, זה שעלה עליו הגורל לעזאזל יתקים תחתיו. והשני ירעה עד שיסתאב, וימכר ויפלו דמיו לנדבה, שאין חטאת צבור מתה. רבי יהודה אומר, תמות. ועוד אמר רבי יהודה, נשפך הדם, ימות המשתלח. מת המשתלח, ישפך הדם.

English Translation
 The two Yom Kippur goats: It is commanded that both of them should be equivalent in appearance, in stature, and in value, and that they are purchased together. However, they are considered fit [for the rite] even if they are not equivalent. [And even] if one is purchased today and the other tomorrow, they are considered fit.

If one of them dies: If it has died prior to the drawing of the lots, [a new goat] should be purchased to compliment the remaining one. But if it died from the drawing of the lots onward, two [new] goats are to be purchased together, and lots drawn over them from the beginning. If [the goat designated] for Adonai has died, is should be recited [over the replacement], “This is [the goat] whose lot was drawn for Adonai, let it stand in place of the one [which died].” If [the goat designated] for Azazel has died, is should be recited [over the replacement], “This is [the goat] whose lot was drawn for Azazel, let it stand in place of the one [which died].” And the other [goat of the pair] is sent to pasture until it becomes unfit for sacrifice. [At that point], it may be sold, and it's value is considered a freewill offering, since [a goat that has been] designated for the public sin offering is not to be slaughtered.

Rabbi Yehuda said that it may be slaughtered.

And Rabbi Yehudah further said, if the blood [of the first goat] were spilled, then the scapegoat [lit. the one which is to be sent] should be slaughtered as well. [Likewise,] if the scapegoat is slaughtered, then the blood [of the first goat] should be spilled. 

Explanation
משנה יומא ו א