Ambrose of Milan
Catena Aurea · Lukasevangelium 21
And there shall be signs in the sun, and in the moon, and in the stars; and upon the earth distress of nations, with perplexity; the sea and the waves roaring; Men’s hearts failing them for fear, and for looking after those things which are coming on the earth: for the powers of heaven shall be shaken. And then shall they see the Son of man coming in a cloud with power and great glory.
While many also fall away from religion, clear faith will be obscured by the cloud of unbelief, for to me that Sun of righteousness is either diminished or increased according to my faith; and as the moon in its monthly wanings, or when it is opposite the sun by the interposition of the earth, suffers eclipse, so also the holy Church when the sins of the flesh oppose the heavenly light, cannot borrow the brightness of divine light from Christ’s rays. For in persecutions, the love of this world generally shuts out the light of the divine Sun; the stars also fall, that is, men who shine in glory fall when the bitterness of persecution waxes sharp and prevails. And this must be until the multitude of the Church be gathered in, for thus are the good tried and the weak made manifest.