Musnad Ahmad Hadith 18480

Affan narrated to us, Shu’bah narrated to us, he said: Zubayd informed me, and Mansur, and Dawud, and Ibn ‘Awn, and Mujalid, from al-Sha’bi, and this is the hadith of Zubayd, he said: I heard al-Sha’bi narrating, from al-Bara’, and he narrated to us near a pillar in the mosque, he said: And if I had been there, I would have informed you of its exact place. He said: The Messenger of Allah, peace and blessings be upon him, addressed us and said: "The first thing we begin with on this day of ours is that we pray, then we return and slaughter. Whoever does that has followed our Sunnah, and whoever slaughters before that, it is only meat he has presented to his family, it is not part of the ritual sacrifice in any way."