Christ Himself, the expectation of the nations, that innumerable posterity once promised to the most blessed patriarch Abraham, but to be born not after the flesh, but by the Spirit, therefore likened to the stars for multitude, that from the father of all nations, not an earthly but an heavenly progeny might be looked for.
Thus the heirs of that promised posterity, marked out in the stars, are roused to the faith by the rise of a new star, and where the heavens had been at first called in to witness, the aid of Heaven is continued.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Serm. 33, 2