Acts 3:12

when Peter saw it i.e. their wonder, as may be inferred from his opening words.

he answered Often used although no previous remark or question precedes. Cp. Acts 5:8, where Peter is said to have answeredSapphira, though she had said nothing, as far as we are told, and where the Apostle's words are a question.

why marvel ye at this?] Probably we should supply man, because the pronoun at the close of the verse is only the personal and not the demonstrative, and we should read "made himto walk," and not as the A. V. "made this manto walk."

look ye so earnestly The verb is rendered "to fasten the eyes on" in Acts 3:4.

by our own power As he had done to the cripple, so also he makes it clear to the crowd that the name of Jesus is the power by which he has wrought.