Will you ask, from whom had they learned that such an appearance as a star was to signify the birth of Christ? I answer from Angels, by the warning of some revelation. Do you ask, was it from good or ill Angels? Truly even wicked spirits, namely the daemons, confessed Christ to be the Son of God. But why should they not have heard it from good Angels, since in this their adoration of Christ their salvation was sought, not their wickedness condemned? The Angels might say to them, ‘The Star which ye have seen is the Christ. Go ye, worship Him, where He is now born, and see how great is He that is born.’
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Serm. 374