We used to perform tamattu in the time of the Messenger of Allah ﷺ, slaughtering a cow on behalf of seven of us, sharing in it together.
حدثنا هشيم أخبرنا عبد الملك عن عطاء
كنا نتمتع في عهد رسول الله ﷺ نذبح البقرة عن سبعة نشترك فيها
Its isnad is sahih. It was previously mentioned at 14163.