'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 mountain and go in search of the one that is lost?

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

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

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