The word(s) "once" appears 85 time(s) in 79 verse(s) in Quran in Muhammad Habib Shakir translation.

(71) Or do they think that We do not hear what they conceal and their secret discourses? Aye! and Our apostles with them write down.

(72) And We gave them clear arguments in the affair, but they did not differ until after knowledge had come to them out of envy among themselves; surely your -Lord will judge between them on the day of resurrection concerning that wherein they differed.

(73) Nay! they say: He has forged it. Say: If I have forged it, you do not control anything for me from Allah; He knows best what you utter concerning it; He is enough as a witness between me and you, and He is the Forgiving, the Merciful.

(74) And those who disbelieve say concerning those who believe: If it had been a good, they would not have gone ahead of us therein. And as they do not seek to be rightly directed thereby, they say: It is an old lie.

(75) So he conceived in his mind a fear on account of them. They said: Fear not. And they gave him the good news of a boy possessing knowledge.

(76) Have you not seen those who have become hypocrites? They say to those of their brethren who disbelieve from among the followers of the Book: If you are driven forth, we shall certainly go forth with you, and we will never obey any one concerning you, and if you are fought against, we will certainly help you, and Allah bears witness that they are most surely liars.

(77) O you who believe! do not take My enemy and your enemy for friends: would you offer them love while they deny what has come to you of the truth, driving out the Apostle and yourselves because you believe in Allah, your Lord? If you go forth struggling hard in My path and seeking My pleasure, would you manifest love to them? And I know what you conceal and what you manifest; and whoever of you does this, he indeed has gone astray from the straight path.

(78) And conceal your word or manifest it; surely He is Cognizant of what is in the hearts.

(79) Nor of the unseen is he a tenacious concealer.