Musannaf Ibn Abi Shayba 33:1015

Mu'awiyah ibn Hisham narrated to us, he said: Sufyan narrated to us, from Abu al-Bakhtari al-Ta'i, he said: He used to say: Envy the living for that which you envy the dead for. And know that worship is not sound except with asceticism and the humiliation of disobedience, and the most beloved of people are those upon their piety.