Musannaf Ibn Abi Shayba 8:3066

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Ibrahim bin Zayd, from Muhammad bin ‘Abbad bin Ja’far, from Ibn ‘Umar, who said: A man stood up to the Prophet, may Allah bless him and grant him peace, and said: "O Messenger of Allah, what makes Hajj obligatory?" He said: "Provisions and a mount." He said: "O Messenger of Allah, what is the pilgrim?" He said: "The disheveled and the dusty." He said: "O Messenger of Allah, what is the best of Hajj?" He said: "Al-‘ajj and al-thajj." He said: "Al-‘ajj is the raising of voices with the Talbiyah, and al-thajj is the slaughtering of the sacrificial animals."