The word(s) "certain" appears 178 time(s) in 176 verse(s) in Quran in Saheeh International translation.

(1) And who believe in what has been revealed to you, [O Muhammad], and what was revealed before you, and of the Hereafter they are certain [in faith].

(2) Who are certain that they will meet their Lord and that they will return to Him.

(3) And We did certainly give Moses the Torah and followed up after him with messengers. And We gave Jesus, the son of Mary, clear proofs and supported him with the Pure Spirit. But is it [not] that every time a messenger came to you, [O Children of Israel], with what your souls did not desire, you were arrogant? And a party [of messengers] you denied and another party you killed.

(4) And Moses had certainly brought you clear proofs. Then you took the calf [in worship] after that, while you were wrongdoers.

(5) And We have certainly revealed to you verses [which are] clear proofs, and no one would deny them except the defiantly disobedient.

(6) And they followed [instead] what the devils had recited during the reign of Solomon. It was not Solomon who disbelieved, but the devils disbelieved, teaching people magic and that which was revealed to the two angels at Babylon, Harut and Marut. But the two angels do not teach anyone unless they say, "We are a trial, so do not disbelieve [by practicing magic]." And [yet] they learn from them that by which they cause separation between a man and his wife. But they do not harm anyone through it except by permission of Allah. And the people learn what harms them and does not benefit them. But the Children of Israel certainly knew that whoever purchased the magic would not have in the Hereafter any share. And wretched is that for which they sold themselves, if they only knew.

(7) Or do you intend to ask your Messenger as Moses was asked before? And whoever exchanges faith for disbelief has certainly strayed from the soundness of the way.

(8) Those who do not know say, "Why does Allah not speak to us or there come to us a sign?" Thus spoke those before them like their words. Their hearts resemble each other. We have shown clearly the signs to a people who are certain [in faith].

(9) We have certainly seen the turning of your face, [O Muhammad], toward the heaven, and We will surely turn you to a qiblah with which you will be pleased. So turn your face toward al-Masjid al-Haram. And wherever you [believers] are, turn your faces toward it [in prayer]. Indeed, those who have been given the Scripture well know that it is the truth from their Lord. And Allah is not unaware of what they do.

(10) And [yet], among the people are those who take other than Allah as equals [to Him]. They love them as they [should] love Allah. But those who believe are stronger in love for Allah. And if only they who have wronged would consider [that] when they see the punishment, [they will be certain] that all power belongs to Allah and that Allah is severe in punishment.