And why are there only seven days in a week?
The Bible is full of numbers especially the Torah, the first five books of the Bible. The concept of gematria replaces each letter with a number. Just as V is a letter it also represents 5 in Roman numerals. The Bible may appear to be words but in actuality it is a string of numbers. Seven, 7, is a key number in the Torah and in other historical societies. The question is why. The key numbers in the Bible are 12, 7, 6 and 40. Think of all the places 12, 7 and 6 appear in our culture. Then think about 40. “It rained for forty days and forty nights.” Forty appears to be of importance in the Torah number scheme but in few other places. Or maybe it disguises itself as 4?