Sinclair Ferguson, The Holy Spirit, InterVarsity Press, 1996, p. 238.
The hallmark of the preaching which the Spirit effects is “boldness”… As in the Old Testament, when the Spirit fills the servant of God He “clothes himself” with that person, and aspects of the Spirit’s authority are illustrated in the courageous declaration of the Word of God. This boldness appears to involve exactly what it denotes: there is freedom of speech. We catch occasional glimpses of this in the Acts of the Apostles. What was said of the early New England preacher Thomas Hooker becomes a visible reality: when he preached, those who heard him felt that he could pick up a king and put him in his pocket!
Sinclair Ferguson, The Holy Spirit, InterVarsity Press, 1996, p. 238.