The New John Gill Exposition of the Entire BibleGenesis 18:28
Peradventure there should lack five of the fifty righteous,
&c.] Or there should be but forty five; for Abraham perceived, by the
Lord's answer, that there were not fifty righteous persons in the place:
wilt thou destroy all the city for [lack of] five?
gradually in his requests, and does not ask too much at once, lest he
should not succeed:
and he said, if l find there forty and five, I will not destroy [it];
that is, forty five righteous persons.