greek syntax principle 16

A singular, anarthrous πας means “every”.

πας οὖν ὅστις ἀκούει μου τοὺς λόγους καὶ ποιεῖ αὐτοὺς ὁμοιωθήσεται ἀνδρὶ φρονίμῳ…

Everyone, therefore, who hears my words…