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

(151) And most of them do not follow (anything) but conjecture; surely conjecture will not avail aught against the truth; surely Allah is cognizant of what they do.

(152) Say: Tell me what Allah has sent down for you of sustenance, then you make (a part) of it unlawful and (a part) lawful. Say: Has Allah commanded you, or do you forge a lie against Allah?

(153) And what will be the thought of those who forge lies against Allah on the day of resurrection? Most surely Allah is the Lord of grace towards men, but most of them do not give thanks.

(154) Those who believe and guarded (against evil):

(155) They say: Allah has taken a son (to Himself)! Glory be to Him: He is the Self-sufficient: His is what is in the heavens and what is in the earth; you have no authority for this; do you say against Allah what you do not know?

(156) Say: Those who forge a lie against Allah shall not be successful.

(157) And recite to them the story of Nuh when he said to his people: O my people! if my stay and my reminding (you) by the communications of Allah is hard on you-- yet on Allah do I rely-- then resolve upon your affair and (gather) your associates, then let not your affair remain dubious to you, then have it executed against me and give me no respite:

(158) Surely those against whom the word of your Lord has proved true will not believe,

(159) And who is more unjust than he who forges a lie against Allah? These shall be brought before their Lord, and the witnesses shall say: These are they who lied against their Lord. Now surely the curse of Allah is on the unjust.

(160) And, O my people! who will help me against Allah if I drive them away? Will you not then mind?