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

(41) The parable of those who take guardians besides Allah is as the parable of the spider that makes for itself a house; and most surely the frailest of the houses is the spider's house did they but know.

(42) He created the heavens without pillars as you see them, and put mountains upon the earth lest it might convulse with you, and He spread in it animals of every kind; and We sent down water from the cloud, then caused to grow therein (vegetation) of every noble kind.

(43) O wives of the Prophet! you are not like any other of the women; If you will be on your guard, then be not soft in (your) speech, lest he in whose heart is a disease yearn; and speak a good word.

(44) Surely Allah upholds the heavens and the earth lest they come to naught; and if they should come to naught, there Is none who can uphold them after Him; surely He is the Forbearing, the Forgiving.

(45) o Dawood! surely We have made you a ruler in the land; so judge between men with justice and do not follow desire, lest it should lead you astray from the path of Allah; (as for) those who go astray from the path of Allah, they shall surely have a severe punishment because they forgot the day of reckoning.

(46) lest a soul should say: O woe to me! for what I fell short of my duty to Allah, and most surely I was of those who laughed to scorn;

(47) And you did not veil yourselves lest your ears and your eyes and your skins should bear witness against you, but you thought that Allah did not know most of what you did.

(48) O you who believe! do not raise your voices above the voice of the Prophet, and do not speak loud to him as you speak loud to one another, lest your deeds became null while you do not perceive.

(49) O you who believe! if an evil-doer comes to you with a report, look carefully into it, lest you harm a people in ignorance, then be sorry for what you have done.

(50) Then shall he be rewarded for it with the fullest reward-