The word(s) "certainty" appears 23 time(s) in 23 verse(s) in Quran in Mohsin Khan translation.

(1) And who believe in (the Qur'an and the Sunnah ) which has been sent down (revealed) to you (O Muhammad صلى الله عليه وسلم) and in that which was sent down before you [the Taurat (Torah) and the Injeel (Gospel), etc.] and they believe with certainty in the Hereafter. (Resurrection, recompense of their good and bad deeds, Paradise and Hell).

(2) And those who have no knowledge say: "Why does not Allah speak to us (face to face) or why does not a sign come to us?" So said the people before them words of similar import. Their hearts are alike, We have indeed made plain the signs for people who believe with certainty.

(3) Then when Talut (Saul) set out with the army, he said: "Verily! Allah will try you by a river. So whoever drinks thereof, he is not of me, and whoever tastes it not, he is of me, except him who takes (thereof) in the hollow of his hand." Yet, they drank thereof, all, except a few of them. So when he had crossed it (the river), he and those who believed with him, they said: "We have no power this day against Jalut (Goliath) and his hosts." But those who knew with certainty that they were going to meet Allah, said: "How often a small group overcame a mighty host by Allah's Leave?" And Allah is with As-Sabirun (the patient).

(4) Thus did we show Ibrahim (Abraham) the kingdom of the heavens and the earth that he be one of those who have Faith with certainty.

(5) And between them will be a (barrier) screen and on Al-A'raf (a wall with elevated places) will be men (whose good and evil deeds would be equal in scale), who would recognise all (of the Paradise and Hell people), by their marks (the dwellers of Paradise by their white faces and the dwellers of Hell by their black faces), they will call out to the dwellers of Paradise, "Salamun 'Alaikum" (Peace be on you), and at that time they (men on Al-A'raf) will not yet have entered it (Paradise), but they will hope to enter (it) with certainty.

(6) Allah is He Who raised the heavens without any pillars that you can see. Then, He rose above (Istawa) the Throne (really in a manner that suits His Majesty). He has subjected the sun and the moon (to continue going round), each running (its course) for a term appointed. He manages and regulates all affairs; He explains the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) in detail, that you may believe with certainty in the meeting with your Lord.

(7) And worship your Lord until there comes unto you the certainty (i.e. death).

(8) [Musa (Moses)] said: "The Lord of the heavens and the earth, and all that is between them, if you seek to be convinced with certainty."

(9) Those who perform As-Salat (Iqamat-as-Salat) and give Zakat and they believe with certainty in the Hereafter (resurrection, recompense of their good and bad deeds, Paradise and Hell).

(10) And when the Word (of torment) is fulfilled against them, We shall bring out from the earth a beast for them, to speak to them because mankind believed not with certainty in Our Ayat (Verses of the Qur'an and Prophet Muhammad صلى الله عليه وسلم).