The word(s) "fulfil" appears 43 time(s) in 42 verse(s) in Quran in Mohsin Khan translation.

(21) And fulfil the Covenant of Allah (Bai'ah: pledge for Islam) when you have covenanted, and break not the oaths after you have confirmed them - and indeed you have appointed Allah your surety. Verily! Allah knows what you do.

(22) And be not like her who undoes the thread which she has spun, after it has become strong, by taking your oaths as a means of deception among yourselves, lest a nation should be more numerous than another nation. Allah only tests you by this [i.e who obeys Allah and fulfils Allah's Covenant and who disobeys Allah and breaks Allah's Covenant]. And on the Day of Resurrection, He will certainly make clear to you that wherein you used to differ [i.e. a believer confesses and believes in the Oneness of Allah and in the Prophethood of Prophet Muhammad صلى الله عليه و سلم which the disbeliever denies and that is their difference amongst them in the life of this world] .

(23) So, when the promise came for the first of the two, We sent against you slaves of Ours given to terrible warfare. They entered the very innermost parts of your homes. And it was a promise (completely) fulfilled.

(24) And come not near to the orphan's property except to improve it, until he attains the age of full strength. And fulfil (every) covenant. Verily, the covenant, will be questioned about.

(25) And they say: "Glory be to our Lord! Truly, the Promise of our Lord must be fulfilled."

(26) Then We fulfilled to them the promise. So We saved them and those whom We willed, but We destroyed Al-Musrifun (i.e. disbelievers in Allah, in His Messengers, extravagants, transgressors of Allah's limits by committing crimes, oppressions, polytheism and sins).

(27) And the true promise (Day of Resurrection) shall draw near (of fulfillment). Then (when mankind is resurrected from their graves), you shall see the eyes of the disbelievers fixedly staring in horror. (They will say): "Woe to us! We were indeed heedless of this - nay, but we were Zalimun (polytheists and wrong-doers)."

(28) For them there will be therein all that they desire, and they will abide (there forever). It is a promise binding upon your Lord that must be fulfilled.

(29) And they (the disbelievers in the Oneness of Allah) say: "When (will) this promise (be fulfilled), if you are truthful?"

(30) And when the Word (of torment) is fulfilled against them, We shall bring out from the earth a beast for them, to speak to them because mankind believed not with certainty in Our Ayat (Verses of the Qur'an and Prophet Muhammad صلى الله عليه وسلم).