The word(s) "duty" appears 132 time(s) in 121 verse(s) in Quran in Muhammad Pickthal translation.

(31) And let those fear (in their behaviour toward orphans) who if they left behind them weak offspring would be afraid for them. So let them mind their duty to Allah, and speak justly.

(32) And all married women (are forbidden unto you) save those (captives) whom your right hands possess. It is a decree of Allah for you. Lawful unto you are all beyond those mentioned, so that ye seek them with your wealth in honest wedlock, not debauchery. And those of whom ye seek content (by marrying them), give unto them their portions as a duty. And there is no sin for you in what ye do by mutual agreement after the duty (hath been done). Lo! Allah is ever Knower, Wise.

(33) Unto Allah belongeth whatsoever is in the heavens and whatsoever is in the earth. And We charged those who received the Scripture before you, and (We charge) you, that ye keep your duty toward Allah. And if ye disbelieve, lo! unto Allah belongeth whatsoever is in the heavens and whatsoever is in the earth, and Allah is ever Absolute, Owner of Praise.

(34) O ye who believe! Profane not Allah's monuments nor the Sacred Month nor the offerings nor the garlands, nor those repairing to the Sacred House, seeking the grace and pleasure of their Lord. But when ye have left the sacred territory, then go hunting (if ye will). And let not your hatred of a folk who (once) stopped your going to the inviolable place of worship seduce you to transgress; but help ye one another unto righteousness and pious duty. Help not one another unto sin and transgression, but keep your duty to Allah. Lo! Allah is severe in punishment.

(35) They ask thee (O Muhammad) what is made lawful for them. Say: (all) good things are made lawful for you. And those beasts and birds of prey which ye have trained as hounds are trained, ye teach them that which Allah taught you; so eat of that which they catch for you and mention Allah's name upon it, and observe your duty to Allah. Lo! Allah is swift to take account.

(36) Remember Allah's grace upon you and His covenant by which He bound you when ye said: We hear and we obey; And keep your duty to Allah. Lo! He knoweth what is in the breasts (of men).

(37) O ye who believe! Be steadfast witnesses for Allah in equity, and let not hatred of any people seduce you that ye deal not justly. Deal justly, that is nearer to your duty. Observe your duty to Allah. Lo! Allah is Informed of what ye do.

(38) O ye who believe! Remember Allah's favour unto you, how a people were minded to stretch out their hands against you but He withheld their hands from you; and keep your duty to Allah. In Allah let believers put their trust.

(39) O ye who believe! Be mindful of your duty to Allah, and seek the way of approach unto Him, and strive in His way in order that ye may succeed.

(40) O Ye who believe! Choose not for guardians such of those who received the Scripture before you, and of the disbelievers, as make a jest and sport of your religion. But keep your duty to Allah if ye are true believers.