Sayyiduna Mu'awiyah bin al-Hakam al-Sulami (may Allah be pleased with him) said: I went to my sheep, which a slave girl of mine was grazing in the direction of Uhud and al-Jawwaniyyah, and I saw that a wolf had taken one of the sheep. I am a man from the children of Adam; I feel regret just as others feel it, so I gave her a slap. Then I went back to the Messenger of Allah (peace and blessings be upon him) and told him, and he (peace and blessings be upon him) took it very seriously. I said: "O Messenger of Allah, shall I not free her?" He (peace and blessings be upon him) said: "Yes, bring her to me." So I brought her to the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) asked her: "Where is Allah?" She said: "Allah, the Mighty and Majestic, is in the heaven." He (peace and blessings be upon him) asked: "Who am I?" She said: "You are the Messenger of Allah." He (peace and blessings be upon him) said: "She is a believer, so free her."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16986