The word(s) "duty" appears 64 time(s) in 61 verse(s) in Quran in Mohsin Khan translation.

(21) Then, if they turn away, your duty (O Muhammad صلى الله عليه و سلم) is only to convey (the Message) in a clear way.

(22) Truly, Allah is with those who fear Him (keep their duty unto Him), and those who are Muhsinun (good-doers. See the footenote of V.9:120).

(23) And verily this your religion (of Islamic Monotheism) is one religion, and I am your Lord, so fear (keep your duty to) Me.

(24) And whosoever obeys Allah and His Messenger (صلى الله عليه وسلم), fears Allah, and keeps his duty (to Him), such are the successful.

(25) Say: "Obey Allah and obey the Messenger, but if you turn away, he (Messenger Muhammad صلى الله عليه وسلم) is only responsible for the duty placed on him (i.e. to convey Allah's Message) and you for that placed on you. If you obey him, you shall be on the right guidance. The Messenger's duty is only to convey (the message) in a clear way (i.e. to preach in a plain way)."

(26) "So fear Allah, keep your duty to Him, and obey me.

(27) "So keep your duty to Allah, fear Him and obey me."

(28) "So fear Allah, keep your duty to Him, and obey me.

(29) "So fear Allah, keep your duty to Him, and obey me.

(30) "And keep your duty to Him, fear Him Who has aided you with all (good things) that you know.