Luke 1:73

73.According to the oath There is no word in the Greek original for the preposition according to: but it is a common and well understood principle of language, that when the accusative case is put absolutely, there is a preposition to be understood, by which it is governed. The oath is mentioned, for the purpose of expressing more fully the firmness and sacredness of his truth: for such is his gracious condescension, that he deigns to employ his name for the support of our weakness. If his bare promises do not satisfy us, let us at least remember this confirmation of them; and if it does not remove all doubt, we are chargeable with heinous ingratitude to God, and insult to his holy name.

To give to us Zacharias does not enumerate the several points of God’s covenant, but shows that God’s purpose, in dealing so kindly and mercifully with his people, was to redeem them.