The word(s) "lest" appears 40 time(s) in 40 verse(s) in Quran in Saheeh International translation.

(1) And We said, "O Adam, dwell, you and your wife, in Paradise and eat therefrom in [ease and] abundance from wherever you will. But do not approach this tree, lest you be among the wrongdoers."

(2) And do not trust except those who follow your religion." Say, "Indeed, the [true] guidance is the guidance of Allah. [Do you fear] lest someone be given [knowledge] like you were given or that they would [thereby] argue with you before your Lord?" Say, "Indeed, [all] bounty is in the hand of Allah - He grants it to whom He wills. And Allah is all-Encompassing and Wise."

(3) O you who have believed, be persistently standing firm in justice, witnesses for Allah, even if it be against yourselves or parents and relatives. Whether one is rich or poor, Allah is more worthy of both. So follow not [personal] inclination, lest you not be just. And if you distort [your testimony] or refuse [to give it], then indeed Allah is ever, with what you do, Acquainted.

(4) They request from you a [legal] ruling. Say, "Allah gives you a ruling concerning one having neither descendants nor ascendants [as heirs]." If a man dies, leaving no child but [only] a sister, she will have half of what he left. And he inherits from her if she [dies and] has no child. But if there are two sisters [or more], they will have two-thirds of what he left. If there are both brothers and sisters, the male will have the share of two females. Allah makes clear to you [His law], lest you go astray. And Allah is Knowing of all things.

(5) O People of the Scripture, there has come to you Our Messenger to make clear to you [the religion] after a period [of suspension] of messengers, lest you say, "There came not to us any bringer of good tidings or a warner." But there has come to you a bringer of good tidings and a warner. And Allah is over all things competent.

(6) And judge, [O Muhammad], between them by what Allah has revealed and do not follow their inclinations and beware of them, lest they tempt you away from some of what Allah has revealed to you. And if they turn away - then know that Allah only intends to afflict them with some of their [own] sins. And indeed, many among the people are defiantly disobedient.

(7) And among them are those who listen to you, but We have placed over their hearts coverings, lest they understand it, and in their ears deafness. And if they should see every sign, they will not believe in it. Even when they come to you arguing with you, those who disbelieve say, "This is not but legends of the former peoples."

(8) And leave those who take their religion as amusement and diversion and whom the worldly life has deluded. But remind with the Qur'an, lest a soul be given up to destruction for what it earned; it will have other than Allah no protector and no intercessor. And if it should offer every compensation, it would not be taken from it. Those are the ones who are given to destruction for what they have earned. For them will be a drink of scalding water and a painful punishment because they used to disbelieve.

(9) And do not insult those they invoke other than Allah, lest they insult Allah in enmity without knowledge. Thus We have made pleasing to every community their deeds. Then to their Lord is their return, and He will inform them about what they used to do.

(10) [We revealed it] lest you say, "The Scripture was only sent down to two groups before us, but we were of their study unaware,"