What Came First?

Boruch: I learned the Daf very well this week, and I can’t really see how it has relevance to practical halacha.
Shimon: The Daf doesn’t have to have any practical relevance. Learning Torah is a mitzvah even if it’s not halacha l’maaseh. Furthermore, the logic behind various scenarios can be applied elsewhere, even if the exact situation discussed in the Gemara doesn’t exist. By the way, I wanted to ask your opinion on an interesting situation. There are two babies having their bris in the same shul with the same mohel. One was born Wednesday morning at 5 am. The other was born at 3 o’clock in the afternoon. Which baby should have his bris milah first?
Boruch: That’s obvious. The baby born in the morning should have his bris first, since he was born first.
Shimon: Actually, from the Daf this week, we learned that there is no preference. The Gemara discusses a goat that was designated for a korban on Yom Kippur. Another goat was designated for the same exact korban. The kohen gadol has to choose which one to bring. The Gemara suggests that even though one was purchased earlier and designated earlier, that itself is not a reason to choose that one. Ultimately, both the original korban and the replacement are not viable until a second lottery is performed. Therefore, they both become viable at the exact same time. (Rashi Yoma 64a D”H B’idna. This logic is the conclusion according to Rav and the Chachomim.) So too, here, although one baby was born earlier, he cannot have his bris until the morning of the eighth day. The baby that was born later can also have his bris performed at the same time on the morning of the eighth day. Since the obligations come at the exact same time, there is no preference to perform the bris on the baby that was born first. However, if this will lead to argument and strife, then the bris should be performed on the baby born first. (Birchas Avrohom OC 14)