Musnad Ahmad 470:1

Sufyan ibn 'Uyaynah narrated to us, twice, he said: Abu al-Za'ra' 'Amr ibn 'Amr narrated to us, from his paternal uncle Abu al-Ahwas, from his father, who said: I came to the Prophet, peace and blessings of Allah be upon him, and he looked at me up and down, and said: "Are you an owner of camels or an owner of sheep?" I said: "Allah has given me of both, and in abundance and goodness." He said: "Do you have them give birth, with their eyes and ears intact, then you slit the ear of one and say: 'It is cut'—then Sufyan spoke a word I did not understand—and you say: 'It is a Bahirah (dedicated) to Allah'? For Allah’s arm is stronger, and His razor is sharper, and if He had willed to bring it to you cut, He would have brought it to you." I said: "To what do you call?" He said: "To Allah and to the ties of kinship." I said: "A man from my cousins comes to me, and I swear not to give him anything, then I give him?" He said: "Expiate your oath, and do that which is better. Have you considered if you had two slaves, one of whom obeys you, does not betray you, and does not lie to you, and the other betrays you and lies to you?" I said: "No, rather the one who does not betray me, does not lie to me, and tells me the truth is more beloved to me." He said: "That is how you are to your Lord, the Mighty and Majestic."