Charles Ellicott Commentary Luke 1:70

"(As he spake by the mouth of his holy prophets that have been from of old)," — Luke 1:70 (ASV)

His holy prophets, which have been since the world began.—The words were probably more than a lofty paraphrase of the more usual language, “of old time,” “of ancient days,” and imply a reference to the great first Gospel, as it has been called, of Genesis 3:15, as well as to those made to Abraham, who is the first person named as a prophet (Genesis 20:7).