Musannaf Ibn Abi Shayba 28:232

Muhammad ibn Fudayl narrated to us, from al-Walid ibn Jumay', who said: A governor of Umar ibn Abd al-Aziz from Yemen wrote to him that a man was a Jew, then he accepted Islam, then he returned to Judaism, so he turned away from Islam. Umar wrote to him: "Invite him to Islam; if he accepts Islam, then let him go. If he refuses, then invite him with kindness, then invite him [again]. If he refuses, then press him upon it. If he refuses, then bind him, then place the wood (spear/staff) upon his heart, then invite him. If he returns [to Islam], then let him go. If he refuses, then kill him." When the letter arrived, he did that to him until he placed the spear upon his heart, then he invited him, so he accepted Islam, and he let him go.