It was narrated from ‘Aishah and Abu Hurairah that when the Messenger of Allah ﷺ wanted to offer a sacrifice, he brought two large, fat, horned, black-and-white, castrated rams. He slaughtered one on behalf of his nation, for whoever testified to Allah with monotheism and that he had conveyed (the Message), and he slaughtered the other on behalf of Muhammad and the family of Muhammad ﷺ. (Using translation from Ibn Mājah 3122)
ؓ أَوْ أَبِي هُرَيْرَةَ ؓ الشَّكُّ مِنْ سُفْيَانَ قَالَ كَانَ رَسُولُ اللهِ ﷺ إِذَا ضَحَّى دَعَا بِكَبْشَيْنِ عَظِيمَيْنِ سَمِينَيْنِ أَمْلَحَيْنِ مُوجَأَيْنِ أَقْرَنَيْنِ فَذَبَحَ أَحَدَهُمَا عَنْ أُمَّتِهِ مَنْ شَهِدَ لَهُ بِالْبَلَاغِ وَشَهِدَ لِلَّهِ بِالتَّوْحِيدِ وَيَذْبَحُ الْآخَرَ عَنْ مُحَمَّدٍ وَآلِ مُحَمَّدٍ