Musannaf Ibn Abi Shayba 19:907

Abu Bakr narrated to us, he said: Abu Dawud al-Tayalisi narrated to us, from Hammam, from Yahya, that the governor of Oman wrote to Umar ibn Abd al-Aziz regarding a sorceress whom he had apprehended. Umar wrote to him: "If she confesses or if the evidence is established against her, then execute her."