The word(s) "brethren" appears 21 time(s) in 21 verse(s) in Quran in Muhammad Pickthal translation.

(1) O ye who believe! Be not as those who disbelieved and said of their brethren who went abroad in the land or were fighting in the field: If they had been (here) with us they would not have died or been killed: that Allah may make it anguish in their hearts. Allah giveth life and causeth death; and Allah is Seer of what ye do.

(2) Those who, while they sat at home, said of their brethren (who were fighting for the cause of Allah): If they had been guided by us they would not have been slain. Say (unto them, O Muhammad): Then avert death from yourselves if ye are truthful.

(3) Allah chargeth you concerning (the provision for) your children: to the male the equivalent of the portion of two females, and if there be women more than two, then theirs is two-thirds of the inheritance, and if there be one (only) then the half. And to each of his parents a sixth of the inheritance, if he have a son; and if he have no son and his parents are his heirs, then to his mother appertaineth the third; and if he have brethren, then to his mother appertaineth the sixth, after any legacy he may have bequeathed, or debt (hath been paid). Your parents and your children: Ye know not which of them is nearer unto you in usefulness. It is an injunction from Allah. Lo! Allah is Knower, Wise.

(4) They ask thee for a pronouncement. Say: Allah hath pronounced for you concerning distant kindred. If a man die childless and he have a sister, hers is half the heritage, and he would have inherited from her had she died childless. And if there be two sisters, then theirs are two-thirds of the heritage, and if they be brethren, men and women, unto the male is the equivalent of the share of two females. Allah expoundeth unto you, so that ye err not. Allah is Knower of all things.

(5) With some of their forefathers and their offspring and their brethren; and We chose them and guided them unto a straight path.

(6) Their brethren plunge them further into error and cease not.

(7) But if they repent and establish worship and pay the poor-due, then are they your brethren in religion. We detail Our revelations for a people who have knowledge.

(8) O ye who believe! Choose not your fathers nor your brethren for friends if they take pleasure in disbelief rather than faith. Whoso of you taketh them for friends, such are wrong-doers.

(9) Say: If your fathers, and your sons, and your brethren, and your wives, and your tribe, and the wealth ye have acquired, and merchandise for which ye fear that there will no sale, and dwellings ye desire are dearer to you than Allah and His messenger and striving in His way: then wait till Allah bringeth His command to pass. Allah guideth not wrongdoing folk.

(10) He said: O my dear son! Tell not thy brethren of thy vision, lest they plot a plot against thee. Lo! Satan is for man an open foe.