“If one should inquire about the reason why we keep such a vigil, the answer is easy to find and give. For He who has granted us the glory of His name has illuminated this night: He to whom we say ‘You shall enlighten darkness’ enlightens our hearts, so that just as our eyes rejoice at this splendor of lighted candles so our minds may be enlightened and shed light on the meaning of this resplendent night.
Why, then, is it that Christians keep vigil on this anniversary night? This is our greatest vigil and no other vigil of similar proportions is known. In answer to our eager query, When do we keep vigil? We reply: Several other vigils are kept by us, but nothing comparable to this vigil. The apostle has urged the faithful to frequent fasting and vigils, recalling his own practice in the words, ‘In toil and hardship, through many a sleepless night, in hunger and thirst’ (2 Corinthians 11:27). But tonight’s vigil is so special that it deserves to appropriate to itself the common title of vigil” (St. Augustine, Sermon 221:2 [HT to A Year with the Church Fathers, ed. Scott Murray])
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