Of all the numbers mentioned in the Bible, 7 is clearly symbolic and likely the most sacred. The number 7 appears more than 600 times in the Bible, but below are some of the most significant mentions:
God rested from Creation on the seventh day
Jacob labored seven years to win the hand of Rachel
In Joseph's time, Egypt suffered seven years of plenty and seven years of famine
God commanded the Israelites to eat unleavened bread for seven days in memory of the exodus from Egypt
Naaman, suffering from leprosy, was told to dip in the Jordan River seven times
The apocalyptic book of Revelation is loaded with sevens, including: seven churches, seven seals, seven angels, seven trumpets, seven golden bowls, seven stars, seven hills, etc.