The word(s) "once" appears 209 time(s) in 198 verse(s) in Quran in Saheeh International translation.

(1) He said, "O Adam, inform them of their names." And when he had informed them of their names, He said, "Did I not tell you that I know the unseen [aspects] of the heavens and the earth? And I know what you reveal and what you have concealed."

(2) We said, "Go down from it, all of you. And when guidance comes to you from Me, whoever follows My guidance - there will be no fear concerning them, nor will they grieve.

(3) And do not mix the truth with falsehood or conceal the truth while you know [it].

(4) Indeed, those who believed and those who were Jews or Christians or Sabeans [before Prophet Muhammad] - those [among them] who believed in Allah and the Last Day and did righteousness - will have their reward with their Lord, and no fear will there be concerning them, nor will they grieve.

(5) And you had already known about those who transgressed among you concerning the sabbath, and We said to them, "Be apes, despised."

(6) And [recall] when you slew a man and disputed over it, but Allah was to bring out that which you were concealing.

(7) But do they not know that Allah knows what they conceal and what they declare?

(8) Yes [on the contrary], whoever submits his face in Islam to Allah while being a doer of good will have his reward with his Lord. And no fear will there be concerning them, nor will they grieve.

(9) The Jews say "The Christians have nothing [true] to stand on," and the Christians say, "The Jews have nothing to stand on," although they [both] recite the Scripture. Thus the polytheists speak the same as their words. But Allah will judge between them on the Day of Resurrection concerning that over which they used to differ.

(10) Or do you say that Abraham and Ishmael and Isaac and Jacob and the Descendants were Jews or Christians? Say, "Are you more knowing or is Allah?" And who is more unjust than one who conceals a testimony he has from Allah? And Allah is not unaware of what you do.