'Ninety nine' in the Bible

“What do you think? If any man has a hundred sheep, and one of them has gone astray, does he not leave the ninety-nine on the mountains and go and search for the one that is straying?

If it turns out that he finds it, truly I say to you, he rejoices over it more than over the ninety-nine which have not gone astray.

“What man among you, if he has a hundred sheep and has lost one of them, does not leave the ninety-nine in the open pasture and go after the one which is lost until he finds it?

I tell you that in the same way, there will be more joy in heaven over one sinner who repents than over ninety-nine righteous persons who need no repentance.