(15) بَابُ إِذَا حَنِثَ نَاسِيًا فِي الأَيْمَانِ
Narrated Al-Bara bin Azib that once he had a guest, so he told his family (on the Day of Id-ul-Adha) that they should slaughter the animal for sacrifice before he returned from the ('Id) prayer in orderthat their guest could take his meal. So his family slaughtered (the animal ) before the prayer. Then they mentioned that event to the Prophet who ordered Al-Bara to slaughter another sacrifice. Al-Bara' said to the Prophet (ﷺ) , "I have a young milch she-goat which is better than two sheep for slaughtering." (The sub-narrator, Ibn 'Aun used to say, "I don't know whether the permission (to slaughter a she-goat as a sacrifice) was especially given to Al-Bara' or if it was in general for all the Muslims.") (See Hadith No. 99, Vol. 2.)
Reference: Sahih al-Bukhari 6673
In-book reference: Book 83, Hadith 51
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 78, Hadith 665