Hazrat Jundub (may Allah be pleased with him) said that the Noble Prophet (peace and blessings be upon him) delivered a sermon after performing the prayer on the day of Eid al-Adha. Then he offered the sacrifice. The Prophet (peace and blessings be upon him) said: Whoever has slaughtered (the animal) before the prayer should offer another animal as a sacrifice in its place, and whoever has not slaughtered before the prayer should slaughter in the name of Allah.
Hadith Referenceاللؤلؤ والمرجان / كتاب الأضاحي / 1280
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 13 كتاب العيدين: 23 باب كلام الإمام والناس في خطبة العيد»
Brief Explanation
According to the majority of scholars, performing the sacrifice (qurbani) is Sunnah, the evidence for which is found in the hadith in Sahih Muslim. The Noble Prophet sallallahu alayhi wa sallam said: Whoever sees the crescent of Dhu al-Hijjah and intends to perform the sacrifice, then he should not cut his hair or nails. Now, in this hadith, the sacrifice is made conditional upon intention, which negates obligation. (According to some scholars, performing the sacrifice is obligatory. Imam Abu Hanifah rahimahullah has declared the sacrifice obligatory upon a person who possesses the nisab of zakat, is a resident, and is not a traveler.)