The word(s) "once" appears 105 time(s) in 102 verse(s) in Quran in Mohsin Khan translation.

(71) Who created the heavens and the earth and all that is between them in six Days. Then He (Istawa ) rose over the Throne (in a manner that suits His Majesty). The Most Gracious (Allah)! Ask Him (O Prophet Muhammad صلى الله عليه وسلم , concerning His Qualities: His rising over His Throne, His creations, etc.), as He is Al-Khabir (The All-Knower of everything i.e. Allah).

(72) [As Shaitan (Satan) has barred them from Allah's Way] so they do not worship (prostrate themselves before) Allah, Who brings to light what is hidden in the heavens and the earth, and knows what you conceal and what you reveal. [Tafsir At-Tabari]

(73) And verily, your Lord knows what their breasts conceal and what they reveal.

(74) And your Lord knows what their breasts conceal, and what they reveal.

(75) Verily, your Lord will judge between them, on the Day of Resurrection, concerning that wherein they used to differ.

(76) Call them (adopted sons) by (the names of) their fathers: that is more just with Allah. But if you know not their father's (names, call them) your brothers in faith and Mawalikum (your freed slaves). And there is no sin on you concerning that in which you made a mistake , except in regard to what your hearts deliberately intend. And Allah is Ever Oft-Forgiving, Most Merciful.

(77) Whether you reveal anything or conceal it, verily, Allah is Ever All-Knower of everything.

(78) People ask you concerning the Hour, say: "The knowledge of it is with Allah only. What do you know? It may be that the Hour is near!"

(79) Those who were deemed weak will say to those who were arrogant: "Nay, but it was your plotting by night and day: when you ordered us to disbelieve in Allah and set up rivals to Him!" And each of them (parties) will conceal their own regrets (for disobeying Allah during this worldly life), when they behold the torment. And We shall put iron collars round the necks of those who disbelieved. Are they requited aught except what they used to do?

(80) And Allah did create you (Adam) from dust, then from Nutfah (male and female discharge semen drops i.e. Adam's offspring), then He made you pairs (male and female). And no female conceives or gives birth but with His Knowledge. And no aged man is granted a length of life nor is a part cut off from his life (or another man's life), but is in a Book (Al-Lauh Al-Mahfuz ) Surely, that is easy for Allah.