Musnad Ahmad 2:211

Muhammad ibn Maysar Abu Sa’d al-Saghani narrated to us, Muhammad ibn Ishaq narrated to us, from Muhammad ibn ‘Amr ibn ‘Ata’, from Malik ibn Aws ibn al-Hadathan, who said: ‘Umar used to swear three oaths, saying: "By Allah, no one is more entitled to this wealth than another, and I am not more entitled to it than anyone else. By Allah, there is no one among the Muslims who does not have a share in this wealth, except for a slave owned by another. But we are according to our stations in the Book of Allah and our division from the Messenger of Allah, peace and blessings of Allah be upon him. So, a man is according to his trial in Islam, a man is according to his precedence in Islam, a man is according to his service in Islam, and a man is according to his need. And by Allah, if I remain for them, the shepherd at the mountain of San’a will surely receive his share of this wealth while he is grazing in his place."