Musnad Ahmad 30:3660

Wahb ibn Jarir narrated to us, my father narrated to us, he said: I heard Yunus ibn Yazid al-Ayli narrating from al-Zuhri, from Sa’id ibn al-Musayyib, from Abu Hurayrah, from the Prophet, peace and blessings of Allah be upon him, who said: "You will find people to be like mines; the best of them in the Pre-Islamic Period (Jahiliyyah) are the best of them in Islam, if they attain understanding (fiqh). And you will find that the best of people in this matter are those who most disliked it before entering into it. And you will find that the worst of people is the two-faced person, who comes to these with one face and to those with another face."