The word(s) "gain" appears 419 time(s) in 395 verse(s) in Quran in Muhammad Habib Shakir translation.

(121) Then there came after them an evil posterity who inherited the Book, taking only the frail good of this low life and saying: It will be forgiven us. And if the like good came to them, they would take it (too). Was not a promise taken from them in the Book that they would not speak anything about Allah but the truth, and they have read what is in it; and the abode of the hereafter is better for those who guard (against evil). Do you not then understand?

(122) And when We shook the mountain over them as if it were a covering overhead, and they thought that it was going to fall down upon them: Take hold of what We have given you with firmness, and be mindful of what is in it, so that you may guard (against evil).

(123) And when your Lord brought forth from the children of Adam, from their backs, their descendants, and made them bear witness against their own souls: Am I not your Lord? They said: Yes! we bear witness. Lest you should say on the day of resurrection: Surely we were heedless of this.

(124) Have they feet with which they walk, or have they hands with which they hold, or have they eyes with which they see, or have they ears with which they hear? Say: Call your associates, then make a struggle (to prevail) against me and give me no respite.

(125) Surely those who guard (against evil), when a visitation from the Shaitan afflicts them they become mindful, then lo! they see.

(126) And when those who disbelieved devised plans against you that they might confine you or slay you or drive you away; and they devised plans and Allah too had arranged a plan; and Allah is the best of planners.

(127) And what (excuse) have they that Allah should not chastise them while they hinder (men) from the Sacred Mosque and they are not (fit to be) guardians of it; its guardians are only those who guard (against evil), but most of them do not know.

(128) And know that whatever thing you gain, a fifth of it is for Allah and for the Apostle and for the near of kin and the orphans and the needy and the wayfarer, if you believe in Allah and in that which We revealed to Our servant, on the day of distinction, the day on which the two parties met; and Allah has power over all things.

(129) Those with whom you make an agreement, then they break their agreement every time and they do not guard (against punishment).

(130) And prepare against them what force you can and horses tied at the frontier, to frighten thereby the enemy of Allah and your enemy and others besides them, whom you do not know (but) Allah knows them; and whatever thing you will spend in Allah's way, it will be paid back to you fully and you shall not be dealt with unjustly.