Musannaf Ibn Abi Shayba 17:1246

Isa ibn Yunus narrated to us, from Abu Bakr al-Shaybani, from Damra ibn Habib, who said: The Messenger of Allah (ﷺ) forbade using the *miswak* (tooth-stick) made from myrtle wood or pomegranate wood. He said: "It stirs up the vein of leprosy."