This was to fulfill what was spoken by the prophet: “I will open My mouth in parables; I will utter things [unknown and unattainable] that have been hidden [from mankind] since the foundation of the world.” [Ps 78:2]
Opening his mouth, Peter said: “Most certainly I understand now that God is not one to show partiality [to people as though Gentiles were excluded from God’s blessing],
But when Paul was about to reply, Gallio said to the Jews, “If it were a matter of some misdemeanor or serious crime, O Jews, I would have reason to put up with you;