'Ninety nine' in the Bible

What do you yourselves think? Suppose a man gets a hundred sheep and one of them strays away, will he not leave the ninety-nine on the hills and go and look for the one that is straying?

And if he succeeds in finding it, in solemn truth I tell you that he rejoices over it more than he does over the ninety-nine that have not gone astray.

"Which of you men, if he has a hundred sheep and has lost one of them, does not leave the ninety-nine in their pasture and go in search of the lost one till he finds it?

I tell you that in the same way there will be rejoicing in Heaven over one repentant sinner--more rejoicing than over ninety-nine blameless persons who have no need of repentance.