Theophylact of Ohrid — as excerpted in the Catena Aurea on Luke 1:54-55

“(vide etiam Tit. Bost.) It might also be applied to Israel after the flesh, seeing that out of that body multitudes believed. But this He did remembering His mercy, for He hath fulfilled what He promised to Abraham, saying, For in thy seed shall all the nations of the earth be blessed. (Gen. 12:3.) This promise then the mother of God called to mind, saying, As he spake to our father Abraham; (Gen. 17:12.) for it was said to Abraham, I will place my covenant between me and thee, and thy seed after thee, for an eternal covenant, that I shall be thy God, and the God of thy seed after thee.”