The number seven indicates completion in the Bible. Since we have all fallen into the snares of Satan, seven fold would indicate full restoration from sin.
[Pro 24:16 KJV] 16 For a just [man] falleth seven times, and riseth up again: but the wicked shall fall into mischief.
Mar 16:9 KJV
Now when [Jesus] was risen early the first [day] of the week, he appeared first to Mary Magdalene, out of whom he had cast seven devils.
Naaman was a warrior, and a favorite of the king he was ready to do whatever it would take to be healed,
2Ki 5:1 KJV
Now Naaman, captain of the host of the king of Syria, was a great man with his master, and honourable, because by him the LORD had given deliverance unto Syria: he was also a mighty man in valour, [but he was] a leper.
2Ki 5:9 KJV
So Naaman came with his horses and with his chariot, and stood at the door of the house of Elisha.
2Ki 5:10 KJV
And Elisha sent a messenger unto him, saying, Go and wash in Jordan seven times, and thy flesh shall come again to thee, and thou shalt be clean.
2Ki 5:11 KJV
But Naaman was wroth, and went away, and said, Behold, I thought, He will surely come out to me, and stand, and call on the name of the LORD his God, and strike his hand over the place, and recover the leper.
2Ki 5:12 KJV
[Are] not Abana and Pharpar, rivers of Damascus, better than all the waters of Israel? may I not wash in them, and be clean? So he turned and went away in a rage.
2Ki 5:13 KJV
And his servants came near, and spake unto him, and said, My father, [if] the prophet had bid thee [do some] great thing, wouldest thou not have done [it]? how much rather then, when he saith to thee, Wash, and be clean?
2Ki 5:14 KJV
Then went he down, and dipped himself seven times in Jordan, according to the saying of the man of God: and his flesh came again like unto the flesh of a little child, and he was clean.