Alumnus of Har Etzion, Rav Yishai has been a Ram at Yeshivat Har Etzion since 2016. The son of an alumnus, Rav Jeselson learned in Yeshivat Makor Chaim before entering Har Etzion. Rav Jeselson completed his Hesder army service in the Nachal Brigade, and then attained semikha from the rabbanut. He is also currently pursuing a degree in Special Education from Herzog College, which he hopes to complete by the end of this academic year (2017). Rav Jeselson currently teaches an Israeli Shiur Bet shiur.