In the Gospel the disciples asked Jesus, “Why do the scribes say that Elijah must come first?”
What led the scribed to say Elijah would come first was that in Second Kings they read that without dying Elijah had been taken up to heaven. Then, Malachi the prophet quoted God as saying, “I will send you Elijah, the prophet before the day of the Lord comes.”
In reply Jesus said that Elijah had already come, but had not been recognized. From that the disciples rightly surmised that Jesus was speaking about John the Baptist.
From that we can learn that the words of the Bible should not always be taken literally. Scholars who know the Bible well tell us that symbolic numbers like 3, 7, and 40 occur time after time. And they tell us that the numbers are not actually to count of things, but they carry some other message. The number Three is often used to tell us we are entering into mystery. It was on the third day that Moses came to the spot for sacrificing Jacob.
As works of literature the books of the Bible are enriched with symbols and figures of speech. People who demand that the numbers be taken literally should not read the Bible.