Musannaf Ibn Abi Shaybah 1815 — What is mentioned about the siwak

Sayyiduna Ali (may Allah be pleased with him) said: When any of you gets up at night, let him use the miswak. For when a man gets up at night, uses the miswak, then performs ablution, then stands for prayer, an angel stands behind him listening to his recitation of the Qur'an. Then it gradually comes so close to him that it places its mouth against his mouth. So whenever he recites a verse, that verse enters the angel's belly.