'Ninety nine' in the Bible

What think you? If a man have a hundred sheep, and one of them go astray, does he not leave the ninety-nine, and go into the mountains, and seek for that which has gone astray?

And if it so be that he find it, verily I say to you, he rejoices over it more than over the ninety-nine that did not go astray.

What man of you that has a hundred sheep, and loses one of them, does not leave the ninety-nine in the desert, and go after that which is lost, till he find it?

I say to you, That thus there shall be joy in heaven over one sinner that repents, more than over ninety-nine just persons, who need no repentance.