The word(s) "lest" appears 51 time(s) in 50 verse(s) in Quran in Muhammad Habib Shakir translation.

(11) Or lest you should say: If the Book had been revealed to us, we would certainly have been better guided than they, so indeed there has come to you clear proof from your Lord, and guidance and mercy. Who then is more unjust than he who rejects Allah's communications and turns away from them? We will reward those who turn away from Our communications with an evil chastisement because they turned away.

(12) And when your Lord brought forth from the children of Adam, from their backs, their descendants, and made them bear witness against their own souls: Am I not your Lord? They said: Yes! we bear witness. lest you should say on the day of resurrection: Surely we were heedless of this.

(13) Surely the vilest of animals, in Allah's sight, are the deaf, the dumb, who do not understand.

(14) And remember when you were few, deemed weak in the land, fearing lest people might carry you off by force, but He sheltered you and strengthened you with His aid and gave you of the good things that you may give thanks.

(15) Surely the vilest of animals in Allah's sight are those who disbelieve, then they would not believe.

(16) And there are some of them who molest the Prophet and say: He is one who believes every thing that he hears; say: A hearer of good for you (who) believes in Allah and believes the faithful and a mercy for those of you who believe; and (as for) those who molest the Apostle of Allah, they shall have a painful punishment.

(17) The hypocrites fear lest a chapter should be sent down to them telling them plainly of what is in their hearts. Say: Go on mocking, surely Allah will bring forth what you fear.

(18) But none believed in Musa except the offspring of his people, on account of the fear of Firon and their chiefs, lest he should persecute them; and most surely Firon was lofty in the land; and most surely he was of the extravagant.

(19) He said: O Nuh! surely he is not of your family; surely he is (the doer of) other than good deeds, therefore ask not of Me that of which you have no knowledge; surely I admonish you lest you may be of the ignorant

(20) And do not incline to those who are unjust, lest the fire touch you, and you have no guardians besides Allah, then you shall not be helped.