Sayyiduna Awf bin Malik (may Allah be pleased with him), meaning the narrator's father, came to the Prophet (peace and blessings be upon him) in old, tattered clothes, and he (peace and blessings be upon him) said: "O Awf bin Malik! Are your camels not born with sound ears, and then you cut some of them and say: This is a bahirah; and you slit the ears of some and say: These are surum? Do not do this. The arm of Allah is stronger than your arm, and the blade of Allah is sharper. Everything that Allah has given you is lawful; do not make anything of your wealth forbidden." Then he said to him: "O Awf bin Malik! Is your slave who obeys you and follows your command dearer to you, or your slave who does not obey you and does not follow your command?" He said: Rather, my slave who obeys me and follows my command. He (peace and blessings be upon him) said: "Such too are you in the sight of your Lord, the Exalted."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16663