Sahih Muslim 5075

Al-Bara' b. 'Azib reported:Allah's Messenger (ﷺ) addressed us on the day of Nahr and said: None should sacrifice the animal unless he has completed the ('Id) prayer. A person said: I have a milch goat of less than one year, better than two fat goats. Thereupon he said: Sacrifice it, and no goat of less than a year of age will be accepted as sacrifice after you

A hadith like this has been narrated on the authority of al-Bara' b. 'Azib through another chain of transmitters

Al-Bara' b. 'Azib reported that Abu Burda slaughtered the animal as a sacrifice before the ('Id) prayer. Thereupon Allah's Apostle (ﷺ) said:Offer a substitute for it (since it does not absolve you of the responsibility of sacrifice). Thereupon he said: Allah's Messenger. I have nothing with me but a goat of less than six months. Shu'ba (one of the narrators) said: I think he (al-Bara' b. 'Azib also) said: And it is better than a goat of one year. Thereupon Allah's Messenger (ﷺ) said: Make it a substitute for that (and sacrifice it), but it will not suffice for anyone (as a sacrifice) after you