Albert Barnes Commentary Acts 18:26

"and he began to speak boldly in the synagogue. But when Priscilla and Aquila heard him, they took him unto them, and expounded unto him the way of God more accurately." — Acts 18:26 (ASV)

And expounded. Explained.

The way of God. Gave him full and ample instructions respecting the Messiah as having already come, and respecting the nature of his work.