Him hath God sent for the same did God send, A.V.; both a ruler for a ruler, A.V. and T.R.; with the hand for by the hand, A.V. and T.R. ( σὺν for ἐν), but giving no clear sense in English. The meaning seems to be that Moses was to rule and save with the strength given him by the angel But it is much simpler to take ἐν χειρὶ as equivalent to the common Hebrew phrase דיָבְ, meaning instrumentality, "by means of," "through," and to join it with "did send."
The angel who spake to Moses in the bush in the Name of God was God's instrument in sending Moses. When an angel gives a message from God, the words are always given as spoken by God himself (see e.g.
Joshua 2:1-3). In this verse Stephen, having with great oratorical skill entranced their attention by his recital of God's marvelous revelation of himself to Moses, now takes them off their guard, and shews how their fathers treated Moses just as they had treated Jesus Christ; and how God in the case of Moses had chosen and magnified the very man whom they had scornfully rejected; just as now he had exalted Jesus Christ to be a Prince and a Savior, whom they had crucified.