'Ninety nine' in the Bible

"What do you think? If a man has a hundred sheep and one of them gets lost, will he not leave the ninety-nine on the hillsides, and go and search for the one that is lost?

And if he finds it, I solemnly say to you, he rejoices over it more than he does over the ninety-nine that did not get lost.

"What man among you, if he has a hundred sheep, and if he loses one of them, does not leave the ninety-nine in the desert and continue to look for the lost one until he finds it?

Just so, I tell you, there will be more joy in heaven over one sinful person who repents than over ninety-nine upright people who do not need any repentance.