'Ninety nine' in the Bible

What think you? If a man has a hundred sheep, and one of them is lost, does he not leave the ninety-nine on the mountain, and go and seek for the lost one?

And if he finds it, I tell you truly that he rejoices over it more than over the ninety-nine which were not lost.

What man of you having a hundred sheep, and losing one of them, does not leave the ninety-nine in the wilderness, and go after the lost sheep till he finds it.

So, I tell you, there shall be joy in heaven over one sinner that changes his mind, more than over ninety-nine righteous persons who do not need a change of mind.