What are "Abirim"?
Radak: They are strong bulls.
Why does it say "ha'Ochal Besar Abirim"?
Rashi: I did not tell you to bring Korbanos because I need to eat. Rather, it is a pleasant spirit in front of Me, that I said and My will was done 1 .
Malbim: Refer to 50:12:1:2.
Sifri (Shelach 107) expounds so from "Re'ach Nicho'ach."