Adam Clarke on Acts 4:30

By stretching forth thine hand to heal - Show that it is thy truth which we proclaim, and confirm it with miracles, and show how highly thou hast magnified thy Son Jesus, whom they have despised and crucified, by causing signs and wonders to be wrought in his name.

Thy holy child Jesus - Του ἁγιου παιδος σου should be translated, thy holy Servant, as in Act 4:25. Δαβιδ παιδος σου, thy servant David, not thy Child David: the word is the same in both places.