The word(s) "ought" appears 153 time(s) in 146 verse(s) in Quran in Abdullah Yusuf Ali translation.

(71) Those who fear their Lord in their most secret thoughts, and who hold the Hour (of Judgment) in awe.

(72) They said, "Have you brought us the Truth, or are you one of those who jest?"

(73) Then they sought a stratagem against him: but We made them the ones that lost most!

(74) Say: "O my Lord! judge Thou in truth!" "Our Lord Most Gracious is the One Whose assistance should be sought against the blasphemies ye utter!"

(75) And strive in His cause as ye ought to strive, (with sincerity and under discipline). He has chosen you, and has imposed no difficulties on you in religion; it is the cult of your father Abraham. It is He Who has named you Muslims, both before and in this (Revelation); that the Messenger may be a witness for you, and ye be witnesses for mankind! So establish regular Prayer, give regular Charity, and hold fast to Allah! He is your Protector - the Best to protect and the Best to help!

(76) "Does he promise that when ye die and become dust and bones, ye shall be brought forth (again)?

(77) Or do they say, "He is possessed"? Nay, he has brought them the Truth, but most of them hate the Truth.

(78) "Did ye then think that We had created you in jest, and that ye would not be brought back to Us (for account)?"

(79) Those who brought forward the lie are a body among yourselves: think it not to be an evil to you; On the contrary it is good for you: to every man among them (will come the punishment) of the sin that he earned, and to him who took on himself the lead among them, will be a penalty grievous.

(80) Why did they not bring four witnesses to prove it? When they have not brought the witnesses, such men, in the sight of Allah, (stand forth) themselves as liars!