Musnad Ahmad 652:51

Yazid narrated to us, Sa'id ibn Abi 'Aruba and Abu al-'Ala' informed us, from Qatadah, from Habib ibn Salim, who said: A man was brought before al-Nu'man ibn Bashir whose wife had made her slave-girl lawful for him. He said: "I will surely judge regarding him with the judgment of the Messenger of Allah (may Allah bless him and grant him peace): If she had made her lawful for him, I will surely flog him one hundred lashes, and if she had not made her lawful for him, I will surely stone him." He said: So he found that she had indeed made her lawful for him, so he flogged him one hundred lashes.