“And Jesus subdued him.” The “him” refers to the demon. This is a good example of how spiritual insight and being a “sympathetic listener” (one who is looking for the author’s meaning, not stumbling at every “possible meaning) is necessary to understand the text. Jesus did not “subdue” the child.
“subdued.” The Greek word translated “subdued” is epitimaō (#2008 ἐπιτιμάω). Usually epitimaō means to express strong disapproval of someone: rebuke, reprove, censure; or to speak seriously, and thus warn in order to prevent or end an action. It can also mean “punish” (cp. BDAG Lexicon). However, in this context, epitimaō has the technical meaning it has in Greek religion of gaining control over a spirit, a demon. Robert Guelich (Word Biblical Commentary: Mark) notes that in contexts like these epitimaō is “a commanding word uttered by God or by his spokesman, by which evil powers are brought into submission.” Jesus subdued the demon by the power of God that he wielded, his power, which he expressed in words.
The demon would not respond to just being “rebuked.” Therefore, we cannot agree that Jesus “reproached the demon for having taken possession of the boy” (Meyer). For a “rebuke” to be effective, the hearer must have a heart to listen to and obey God, and demons do not have that kind of heart. The demon had to be dealt with by spiritual power. See commentary on Mark 1:25.