If we this day - If as is the fact; or since we are thus examined.
Examined - Questioned; if the purpose is to institute an inquiry into this case, or since it is the purpose to institute such an inquiry.
The good deed - The act of benevolence; the benefit conferred on an infirm man. He assumes that it was undeniable that the deed had been done.
To the impotent man - To this man who was infirm or lame. The man was then present, Acts 4:10, Acts 4:14. He may have been arrested with the apostles; or he may have been present as a spectator; or, as Neander supposes, he may have been summoned as a witness.
By what means - This was the real point of the inquiry. The fact that he had been made whole was not denied. The only question was whether it had been done by the authority and power of Jesus of Nazareth, as Peter declared it to be, Acts 3:6, Acts 3:16.