"For as Jonah was three days and three nights in the belly of a huge fish, so the Son of Man will be three days and three nights in the heart of the earth."
Mt 12:40


Problem:  Jesus said that he would be in the grave for three days and three nights.  Why do we Catholics celebrate the Triduum with only two nights instead of three?

First, we must consider how the Jews themselves often reckoned days.  The day, or more accurately, the "night-day",  started at sunset and continued until the following sunset.  For counting purposes, any part of one day was considered as a whole day, that is, "a part of the day is as the whole."  So Friday afternoon until sunset would be one night-day, the sabbath day from Friday sunset until the next sunset would be one night-day,   and the sunset through the morning of the next day, "the first day" would be considered one night-day, for a total of three night-days.   This is not how we reckon days now, but we can see at least three examples of this elsewhere in the scriptures:  I Samuel 30:12-13, Esther 4:16, 5:1, and again in Mt 27:63-64.  Remember too that Jesus taught that he would rise "on the third day" (Matthew 16:21), not "on the fourth day."

Secondly, Jesus is alluding to Jonah 2 (Septuagint) in this verse, and we must not take this verse out of context.  The whole section from which it is taken, Mt. 12:38-41 alludes to the story of Jonah's deliverance from the belly of a "whale".  Jesus is deliberately reminding his apostles of Jonah's deliverance which is meant to prefigure His own resurrection.  Moreover, Jonah's prayer in Jonah 2 might in many ways be Jesus' prayer too.

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