Bede

Whoever is simple, let him come to me, etc. He calls the humble the simple; he calls the foolish those who have no arrogance of worldly wisdom. But he calls such to make them wise and noble by his teaching.

Commentary on Proverbs ↗

Hippolytus of Rome

"Whoso is simple, Let him turn to me," she says, alluding manifestly to the holy apostles, who traversed the whole world, and called the nations to the knowledge of Him in truth, with their lofty and divine preaching. And again, "And to those that want understanding she said"-that is, to those who have not yet obtained the power of the Holy Ghost.

Hippolytus Exegetical Fragments ↗