Abdullah bin Sa'id bin Abi Hind عبد الله بن سعيد بن أبي هند · Chapters on Sacrifices

“I asked Ibn ‘Umar about sacrifices and whether they are obligatory. He said: ‘The Messenger of Allah (ﷺ) and the Muslims after him offered sacrifices, and this is the Sunnah.’” Another chain reports exactly the same.

“The Messenger of Allah (ﷺ) sacrificed a horned, defectless ram with a black stomach, black feet and black around its eyes.”