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

(181) And We guard it against every accursed Shaitan,

(182) Surely those who guard (against evil) shall be in the midst of gardens and fountains:

(183) And guard against (the punishment of) Allah and do not put me to shame.

(184) Surely We will suffice you against the scoffers

(185) And it is said to those who guard (against evil): What is it that your Lord has revealed? They say, Good. For those who do good in this world is good, and certainly the abode of the hereafter is better; and certainly most excellent is the abode of those who guard (against evil);

(186) The gardens of perpetuity, they shall enter them, rivers flowing beneath them; they shall have in them what they please. Thus does Allah reward those who guard (against evil),

(187) And certainly We raised in every nation an apostle saying: Serve Allah and shun the Shaitan. So there were some of them whom Allah guided and there were others against whom error was due; therefore travel in the land, then see what was the end of the rejecters.

(188) And whatever is in the heavens and the earth is His, and to Him should obedience be (rendered) constantly; will you then guard against other than (the punishment of) Allah?

(189) And on the day when We will raise up in every people a witness against them from among themselves, and bring you as a witness against these-- and We have revealed the Book to you explaining clearly everything, and a guidance and mercy and good news for those who submit.

(190) And, for what your tongues describe, do not utter the lie, (saying) This is lawful and this is unlawful, in order to forge a lie against Allah; surely those who forge the lie against Allah shall not prosper.