The word(s) "obstinate" appears 18 time(s) in 18 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) And those who, having done something to be ashamed of, or wronged their own souls, earnestly bring Allah to mind, and ask for forgiveness for their sins,- and who can forgive sins except Allah?- and are never obstinate in persisting knowingly in (the wrong) they have done.

(2) The Jews say: "Allah's hand is tied up." Be their hands tied up and be they accursed for the (blasphemy) they utter. Nay, both His hands are widely outstretched: He giveth and spendeth (of His bounty) as He pleaseth. But the revelation that cometh to thee from Allah increaseth in most of them their obstinate rebellion and blasphemy. Amongst them we have placed enmity and hatred till the Day of Judgment. Every time they kindle the fire of war, Allah doth extinguish it; but they (ever) strive to do mischief on earth. And Allah loveth not those who do mischief.

(3) Say: "O People of the Book! ye have no ground to stand upon unless ye stand fast by the Law, the Gospel, and all the revelation that has come to you from your Lord." It is the revelation that cometh to thee from thy Lord, that increaseth in most of them their obstinate rebellion and blasphemy. But sorrow thou not over (these) people without Faith.

(4) If they could find a place to flee to, or caves, or a place of concealment, they would turn straightaway thereto, with an obstinate rush.

(5) Certain of the desert Arabs round about you are hypocrites, as well as (desert Arabs) among the Medina folk: they are obstinate in hypocrisy: thou knowest them not: We know them: twice shall We punish them: and in addition shall they be sent to a grievous penalty.

(6) Such were the 'Ad People: they rejected the Signs of their Lord and Cherisher; disobeyed His messengers; And followed the command of every powerful, obstinate transgressor.

(7) But they sought victory and decision (there and then), and frustration was the lot of every powerful obstinate transgressor.

(8) "As for the youth, his parents were people of Faith, and we feared that he would grieve them by obstinate rebellion and ingratitude (to Allah and man).

(9) Then shall We certainly drag out from every sect all those who were worst in obstinate rebellion against (Allah) Most Gracious.

(10) And yet among men there are such as dispute about Allah, without knowledge, and follow every evil one obstinate in rebellion!