John 4:40 - Clarke's commentary and critical notes on the Bible

So when the Samaritans were come unto him, they besought him that he would tarry with them: and he abode there two days. He abode there two days - We are not told that he wrought any miracles among them; this does not appear to have been necessary: they were a simple-hearted, teachable people, and they credited him on the evidence of his own eternal truth. Why are not miracles wrought now? Miracles were only for the establishment of the doctrines of Christianity, where they were first preached; we profess to believe these doctrines; therefore, to us, miracles would be useless. Where the doctrine is credited, no miracle is necessary: the Samaritans believed, and no miracle was wrought among them; for the simple reason, it was not necessary.