The word(s) "assumption" appears 18 time(s) in 15 verse(s) in Quran in Saheeh International translation.

(1) And [for] their saying, "Indeed, we have killed the Messiah, Jesus, the son of Mary, the messenger of Allah." And they did not kill him, nor did they crucify him; but [another] was made to resemble him to them. And indeed, those who differ over it are in doubt about it. They have no knowledge of it except the following of assumption. And they did not kill him, for certain.

(2) And if you obey most of those upon the earth, they will mislead you from the way of Allah. They follow not except assumption, and they are not but falsifying.

(3) Those who associated with Allah will say, "If Allah had willed, we would not have associated [anything] and neither would our fathers, nor would we have prohibited anything." Likewise did those before deny until they tasted Our punishment. Say, "Do you have any knowledge that you can produce for us? You follow not except assumption, and you are not but falsifying."

(4) And most of them follow not except assumption. Indeed, assumption avails not against the truth at all. Indeed, Allah is Knowing of what they do.

(5) Unquestionably, to Allah belongs whoever is in the heavens and whoever is on the earth. And those who invoke other than Allah do not [actually] follow [His] "partners." They follow not except assumption, and they are not but falsifying

(6) [Remember] when they came at you from above you and from below you, and when eyes shifted [in fear], and hearts reached the throats and you assumed about Allah [various] assumptions.

(7) And Iblees had already confirmed through them his assumption, so they followed him, except for a party of believers.

(8) And We did not create the heaven and the earth and that between them aimlessly. That is the assumption of those who disbelieve, so woe to those who disbelieve from the Fire.

(9) And that was your assumption which you assumed about your Lord. It has brought you to ruin, and you have become among the losers."

(10) And when it was said, 'Indeed, the promise of Allah is truth and the Hour [is coming] - no doubt about it,' you said, 'We know not what is the Hour. We assume only assumption, and we are not convinced.' "