The word(s) "lest" appears 66 time(s) in 65 verse(s) in Quran in Mohsin Khan translation.

(21) And incline not toward those who do wrong, lest the Fire should touch you, and you have no protectors other than Allah, nor you would then be helped.

(22) He (the father) said: "O my son! Relate not your vision to your brothers, lest they should arrange a plot against you. Verily! Shaitan (Satan) is to man an open enemy!

(23) He [Ya'qub (Jacob)] said: "Truly, it saddens me that you should take him away. I fear lest a wolf should devour him, while you are careless of him."

(24) And We turned (the towns of Sodom in Palestine) upside down and rained down on them stones of baked clay.

(25) And He has affixed into the earth mountains standing firm, lest it should shake with you; and rivers and roads, that you may guide yourselves.

(26) And be not like her who undoes the thread which she has spun, after it has become strong, by taking your oaths as a means of deception among yourselves, lest a nation should be more numerous than another nation. Allah only tests you by this [i.e who obeys Allah and fulfils Allah's Covenant and who disobeys Allah and breaks Allah's Covenant]. And on the Day of Resurrection, He will certainly make clear to you that wherein you used to differ [i.e. a believer confesses and believes in the Oneness of Allah and in the Prophethood of Prophet Muhammad صلى الله عليه و سلم which the disbeliever denies and that is their difference amongst them in the life of this world] .

(27) And make not your oaths a means of deception among yourselves, lest a foot should slip after being firmly planted, and you may have to taste the evil (punishment in this world) of having hindered (men) from the Path of Allah (i.e. Belief in the Oneness of Allah and His Messenger, Muhammad صلى الله عليه و سلم), and yours will be a great torment (i.e. the Fire of Hell in the Hereafter).

(28) This is (part) of Al-Hikmah (wisdom, good manners and high character) which your Lord has revealed to you (O Muhammad صلى الله عليه و سلم). And set not up with Allah any other ilah (god) lest you should be thrown into Hell, blameworthy and rejected, (from Allah's Mercy).

(29) And We have put coverings over their hearts lest they should understand it (the Qur'an), and in their ears deafness. And when you make mention of your Lord Alone [La ilaha illallah (none has the right to be worshipped but Allah) Islamic Monotheism (توحيد الله)] in the Qur'an, they turn on their backs, fleeing in extreme dislike.

(30) And who does more wrong than he who is reminded of the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) of his Lord, but turns away from them, forgetting what (deeds) his hands have sent forth. Truly, We have set veils over their hearts lest they should understand this (the Qur'an), and in their ears, deafness. And if you (O Muhammad صلى الله عليه وسلم) call them to guidance, even then they will never be guided.