The Circumcision of Christ is commemorated on the eighth day after His Nativity.

If he was not flesh, why was Mary introduced at all? And if he was not God, whom was Gabriel calling Lord?

If he was not flesh, who was lying in the manger? And if he was not God, whom did the Angels come down and glorify?

If he was not flesh, who was wrapped in swaddling clothes? And if he was not God, whom did the shepherds worship?

If he was not flesh, whom did Joseph circumcise? And if he was not God, in whose honour did the star speed through the heavens?

If he was not flesh, whom did Mary suckle? And if he was not God, to whom did the Magi offer gifts?

-St. Ephraim the Syrian

The full quote is here.