Origen

But as, at the dispensation of the Cross, the sun was eclipsed, and darkness was spread over the earth; so when the sign of the Son of Man appears in heaven, the light of the sun, moon, and stars, shall fail, as though waning before the might of that sign. This we understand to be the sign of the cross, that the Jews may see, as Zacharias and John speak, Him whom they have pierced, (Zech. 12:10. John 19:37.) and the sign of victory.