The word(s) "duty" appears 86 time(s) in 79 verse(s) in Quran in Muhammad Habib Shakir translation.

(11) And for the divorced women (too) provision (must be made) according to usage; (this is) a duty on those who guard (against evil).

(12) O you who believe! Be careful of (your duty to) Allah and relinquish what remains (due) from usury, if you are believers.

(13) O you who believe! when you deal with each other in contracting a debt for a fixed time, then write it down; and let a scribe write it down between you with fairness; and the scribe should not refuse to write as Allah has taught him, so he should write; and let him who owes the debt dictate, and he should be careful of (his duty to) Allah, his Lord, and not diminish anything from it; but if he who owes the debt is unsound in understanding, or weak, or (if) he is not able to dictate himself, let his guardian dictate with fairness; and call in to witness from among your men two witnesses; but if there are not two men, then one man and two women from among those whom you choose to be witnesses, so that if one of the two errs, the second of the two may remind the other; and the witnesses should not refuse when they are summoned; and be not averse to writing it (whether it is) small or large, with the time of its falling due; this is more equitable in the sight of Allah and assures greater accuracy in testimony, and the nearest (way) that you may not entertain doubts (afterwards), except when it is ready merchandise which you give and take among yourselves from hand to hand, then there is no blame on you in not writing it down; and have witnesses when you barter with one another, and let no harm be done to the scribe or to the witness; and if you do (it) then surely it will be a transgression in you, and be careful of (your duty) to Allah, Allah teaches you, and Allah knows all things.

(14) And if you are upon a journey and you do not find a scribe, then (there may be) a security taken into possession; but if one of you trusts another, then he who is trusted should deliver his trust, and let him be careful (of his duty to) Allah, his Lord; and do not conceal testimony, and whoever conceals it, his heart is surely sinful; and Allah knows what you do.

(15) Allah does not impose upon any soul a duty but to the extent of its ability; for it is (the benefit of) what it has earned and upon it (the evil of) what it has wrought: Our Lord! do not punish us if we forget or make a mistake; Our Lord! do not lay on us a burden as Thou didst lay on those before us, Our Lord do not impose upon us that which we have not the strength to bear; and pardon us and grant us protection and have mercy on us, Thou art our Patron, so help us against the unbelieving people.

(16) And a verifier of that which is before me of the Taurat and that I may allow you part of that which has been forbidden t you, and I have come to you with a sign from your Lord therefore be careful of (your duty to) Allah and obey me.

(17) O you who believe! be careful of (your duty to) Allah with the care which is due to Him, and do not die unless you are Muslims.

(18) And Allah did certainly assist you at Badr when you were weak; be careful of (your duty to) Allah then, that you may give thanks.

(19) O you who believe! do not devour usury, making it double and redouble, and be careful of (your duty to) Allah, that you may be successful.

(20) But as to those who are careful of (their duty to) their Lord, they shall have gardens beneath which rivers flow, abiding in them; an entertainment from their Lord, and that which is with Allah is best for the righteous.