Cabalist; lived at Jerusalem in the seventeenth century. He, together with David Yiẓḥaḳi and Jacob Molko, was dayyan in the rabbinate of Moses Galante. A decision by Ḥayyun concerning the dispute between Mordecai ha-Levi, chief rabbi of Cairo, and Judah Ḥabillo, rabbi of Alexandria, is published in the former's "Darke No'am" on the Shulḥan 'Aruk, Ḥoshen Mishpaṭ (Nos. 47, 48). He was the author of a commentary on the Zohar, of which only a small part was published, under the title "Maḥaneh Aharon" (Leghorn, 1795).