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

(41) They ask you about the windfalls. Say: The windfalls are for Allah and the Apostle. So be careful of (your duty to) Allah and set aright matters of your difference, and obey Allah and His Apostle if you are believers.

(42) O you who believe! If you are careful of (your duty to) Allah, He will grant you a distinction and do away with your evils and forgive you; and Allah is the Lord of mighty grace.

(43) Eat then of the lawful and good (things) which you have acquired in war, and be careful of (your duty to) Allah; surely Allah is Forgiving, Merciful.

(44) Except those of the idolaters with whom you made an agreement, then they have not failed you in anything and have not backed up any one against you, so fulfill their agreement to the end of their term; surely Allah loves those who are careful (of their duty).

(45) How can there be an agreement for the idolaters with Allah and with His Apostle; except those with whom you made an agreement at the Sacred Mosque? So as long as they are true to you, be true to them; surely Allah loves those who are careful (of their duty).

(46) O you who believe! be careful of (your duty to) Allah and be with the true ones.

(47) Then when they despaired of him, they retired, conferring privately together. The eldest of them said: Do you not know that your father took from you a covenant in Allah's name, and how you fell short of your duty with respect to Yusuf before? Therefore I will by no means depart from this land until my father permits me or Allah decides for me, and He is the best of the judges:

(48) He sends down the angels with the inspiration by His commandment on whom He pleases of His servants, saying: Give the warning that there is no god but Me, therefore be careful (of your duty) to Me.

(49) And surely this your religion is one religion and I am your Lord, therefore be careful (of your duty) to Me.

(50) And he who obeys Allah and His Apostle, and fears Allah, and is careful of (his duty to) Him, these it is that are the achievers.