Acts 13 :12

Doctrine - The act or result of teaching.

The deputy - believed - This was a proof that the doctrine was true; and that the power of God, from which nothing could be concealed, and which nothing could resist, was with these preachers.

Being astonished - Εκπλησσομενος, Being struck with astonishment, as Elymas was struck with blindness. Thus the word of God is a two-edged sword: it smites the sinner with judgment or compunction; and the sincere inquirer after truth, with conviction of its own worth and excellence.

Then the deputy ...believed - Was convinced that Elymas was an impostor, and that the doctrine of Paul was true. There seems no reason to doubt that his faith was what is connected with eternal life; and if so, it is an evidence that the gospel was not always confined to the poor, and to those in obscure ranks of life.

At the doctrine of the Lord - The word "doctrine" here seems to denote, not the "teaching" or "instruction," but the wonderful effects which were connected with the doctrine. It was particularly the miracle with which he was astonished; but he might have been also deeply impressed and amazed at the purity and sublimity of the truths which were now expanded to his view. We learn nothing further respecting him in the New Testament.

13:12 Being astonished at the doctrine of the Lord - Confirmed by such a miracle.