 He made his solemn profession into the hands of the order's superior Matteo de Modena.It was Brother Matteo who later selected Celli to preach and hear confessions in the region despite the latter not being an ordained priest - though he was soon ordained as such at the successful conclusion of his ecclesiastical studies.It was during this period that he preached against the heresies of Catharism and he even met the famous heretic Armanno Pungilupo.