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

(61) So she conceived him, and she withdrew with him to a far place (i.e. Bethlehem valley about 4-6 miles from Jerusalem).

(62) Thereof (the earth) We created you, and into it We shall return you, and from it We shall bring you out once again.

(63) So Musa (Moses) conceived fear in himself.

(64) And they ask you concerning the mountains: say, "My Lord will blast them and scatter them as particles of dust.

(65) With their hearts occupied (with evil things). Those who do wrong, conceal their private counsels, (saying): "Is this (Muhammad صلى الله عليه وسلم) more than a human being like you? Will you submit to magic while you see it?"

(66) (Say O Muhammad صلى الله عليه وسلم): Verily, He (Allah) knows that which is spoken aloud (openly) and that which you conceal.

(67) And among mankind is he who disputes concerning Allah, without knowledge, and follows every rebellious (disobedient to Allah) Shaitan (devil) (devoid of every kind of good).

(68) There is no sin on you that you enter (without taking permission) houses uninhabited (i.e. not possessed by anybody), (when) you have any interest in them. And Allah has knowledge of what you reveal and what you conceal.

(69) And those who disbelieve say: "Why is not the Qur'an revealed to him all at once?" Thus (it is sent down in parts), that We may strengthen your heart thereby. And We have revealed it to you gradually, in stages. (It was revealed to the Prophet صلى الله عليه وسلم in 23 years.).

(70) Then We withdraw it to Us a gradual concealed withdrawal.