John Chrysostom

And yet it was "the faith which is in Him" (as its object) that did all. For the Apostles did not say, "By the name," but, "In the name," and it was in Him that the man believed. But they did not yet make bold to use the expression, "The faith which is in Him." For, that the phrase "By Him" should not be too low, observe that after saying, "Upon the faith of His name," he adds, "His name hath made him strong," and then it is that he says, "Yea, the faith which is by Him hath given him this perfect soundness." Observe how he implies, …

Homily on Acts 9 ↗

Theophylact of Ohrid

"Through faith in His name, His name has strengthened this man." He speaks thus because the healed man believed as a result of the healing. Does this mean, then, that the lame man stood firmly on his feet by believing in the name of Christ? Even before he believed, the name of Christ, having been invoked, already "strengthened" him. So great is the power it possesses and so many are the gifts of grace it pours forth. …

Commentary on Acts ↗

Oecumenius

What then is the faith proclaimed through him? He explains it himself. "That they may know you the only true one," (Jn. 17:3) and then: Then, for fear that anyone say, "Therefore even an unbeliever will call upon his name, and even when treating an unbeliever the healing will nonetheless proceed, if the mere call of the name were what secured it"—so that no one may say this, he adds, "And the faith which is through him." That is, the name is indeed great and a source of healings, but souls capable of being deemed worthy of grace are …

Commentary on Acts ↗