Charles Spurgeon Commentary Acts 4:13

"Now when they beheld the boldness of Peter and John, and had perceived that they were unlearned and ignorant men, they marvelled; and they took knowledge of them, that they had been with Jesus." — Acts 4:13 (ASV)

Where else could such holy courage have been learned? They spoke in their measure just as the great Master did, of whom it is written: He spoke as one having authority, and not as the Scribes.

They did not speak with the timid, hesitating manner of a preacher who seems to hold the balance of probabilities between the right and the wrong, the false and the true, but with the demonstration of a hearty conviction of the truth of the principles which they uttered.

So Christ spoke, and, having learned of him, so spoke his disciples.