Al-Bara’ said:
The Prophet addressed us on the day of sacrifice saying, “The first thing we do on this day of ours is to pray; then we return and sacrifice. If anyone does that he has correctly followed our custom; but if anyone makes sacrifice before praying, it is only mutton* he has got ready beforehand for his family, and has nothing to do with the rites."
*It counts merely as ordinary food, and is not reckoned as a sacrifice.
(Bukhari and Muslim.)