We performed Hajj Tamattu' along with Allah's Messenger (ﷺ) and we slaughtered a cow on behalf of seven persons sharing in it.
Sahih Muslim Book 15, Hadith 394
← Previous Hadith He (the Holy Prophet) commanded us as we had entered into the state of Ihram to sacrifice the animals (as a rite of Hajj) and a group (of person; amongst us, i. e. seven) shared in the sacrifice of one (camel or cow), and it happened at that time when he commanded them to put off Ihram for Hajj (after performing 'Umra).

Sahih Muslim Book 15, Hadith 393 Next Hadith → Jabir reported that Allah's Messenger (ﷺ) sacrificed a cow on behalf of 'A'isha on the Day of Nahr (10th of Dhu'l-Hijja).

Sahih Muslim Book 15, Hadith 395