Musnad Abu Ya'la al-Mawsili 150:235

Abu Hisham al-Rifa'i narrated to us, Ishaq bin Sulayman al-Razi narrated to us, from Mu'awiyah bin Yahya al-Sadafi, from al-Zuhri, from 'Urwah, from 'Aishah, who said: The Messenger of Allah (ﷺ) was praying in my house. Ali bin Abi Talib approached and stood beside him on his right side. A scorpion approached toward the Prophet (ﷺ), and when it drew near him, it turned away from him. Then it approached toward Ali, so he took his sandal and killed it while he was praying. When he finished his prayer, he said: "May Allah fight it! It approached toward the Prophet (ﷺ), then turned away from him, then approached toward me, wanting me." The Messenger of Allah (ﷺ) did not see any harm in killing it during the prayer.