Today, the birthday of our Lord Jesus Christ has dawned in festive splendor for us. It is His birthday, the day on which the Eternal Day was born. And hence it is this day because from this day forward the length of the day increases. Our Lord had two nativities: one divine, the other, human; both marvelous; the one without a woman as mother, the other without a man as father. Hence, the words of the Prophet Isaias may be applied to both generations: ‘Who shall declare his generation?’ Who would worthily tell of a God generating [His Son]? Who would worthily relate the parturition of a virgin? The former generation took place without the limits of time; the latter, on a definite day in time. Both happened without human calculation, and both are viewed with intense admiration. Consider that first generation: ‘In the beginning was the Word, and the Word was with God; and the Word was God.’ Whose Word? That of the Father Himself. What Word? The Son Himself. Never did the Father exist without the Son, yet He who was never without the Son generated that Son. He generated Him, yet the Son had no beginning, for there is no beginning for Him who was generated without beginning. Nevertheless, He is the Son and He was generated. Someone is going to say: ‘How was He generated if He had ho beginning? If He was generated, He has a beginning; if he has no beginning, then, how was He generated?’ I do not know how this happened. Do you ask me, a mere man, how God was generated? I am troubled by your question, but I have recourse to the words of the Prophet: ‘Who shall declare his generation?’