The word(s) "proof" appears 241 time(s) in 235 verse(s) in Quran in Mohsin Khan translation.

(131) And you might have seen the sun, when it rose, declining to the right from their Cave, and when it set, turning away from them to the left, while they lay in the midst of the Cave. That is (one) of the Ayat (proofs, evidence, signs) of Allah. He whom Allah guides, he is the rightly guided; but he whom He sends astray, for him you will find no Wali (guiding friend) to lead him (to the right Path).

(132) (Some) say they were three, the dog being the fourth among them; and (others) say they were five, the dog being the sixth, - guessing at the unseen; (yet others) say they were seven, and the dog being the eighth. Say (O Muhammad صلى الله عليه وسلم): "My Lord knows best their number; none knows them but a few." So debate not (about their number) except with the clear proof (which We have revealed to you). And consult not any of them (people of the Scripture - Jews and Christians) about (the affair of) the people of the Cave.

(133) And We send not the Messengers except as givers of glad tidings and warners. But those who disbelieve, dispute with false argument, in order to refute the truth thereby. And they treat My Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.), and that with which they are warned, as a jest and mockery!

(134) 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.

(135) "They are those who deny the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) of their Lord and the Meeting with Him (in the Hereafter). So their works are in vain, and on the Day of Resurrection, We shall assign no weight for them.

(136) "That shall be their recompense, Hell; because they disbelieved and took My Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) and My Messengers by way of jest and mockery.

(137) "Go you and your brother with My Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.), and do not, you both, slacken and become weak in My Remembrance.

(138) Eat and pasture your cattle (therein); verily, in this are Ayat (proofs and signs) for men of understanding.

(139) (Allah) will say: "Like this: Our Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) came unto you, but you disregarded them (i.e. you left them, did not think deeply in them, and you turned away from them), and so this Day, you will be neglected (in the Hell-fire, away from Allah's Mercy)."

(140) And thus do We requite him who transgresses beyond bounds [i.e. commits the great sins and disobeys his Lord (Allah) and believes not in His Messengers, and His revealed Books, like this Qur'an], and believes not in the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) of his Lord; and the torment of the Hereafter is far more severe and more lasting.