Ecstatic prophecy is characteristic of the prophetic movement (Montanism) that emerged in Christian circles in the second half of the second century. The so called Montanists spread and diversified quickly within the congregations of the Roman Empire and provoked immediate opposition. One such early opponent of Montanism can be reconstructed from the 48th chapter of Epiphanius' Panarion. This opponent polemicises against the Montanist charismatic demands. The Montanist own arguments can also be inferred from the opponent's argumentation, as well as seven oracles spoken by Maximilla and Montanus. This study identifies Epiphanius' source as the earliest reconstructed source on Montanism. It is argued that the author of this source is the apologist Miltiades. In addition, Montanus' and Maximilla's oracles are made the subject of a detailed interpretation, and their biblical background is highlighted.