The word(s) "swear" appears 21 time(s) in 19 verse(s) in Quran in Abdullah Yusuf Ali translation.

(11) And there are those who put up a mosque by way of mischief and infidelity - to disunite the Believers - and in preparation for one who warred against Allah and His Messenger aforetime. They will indeed swear that their intention is nothing but good; But Allah doth declare that they are certainly liars.

(12) (Jacob) said: "Never will I send him with you until ye swear a solemn oath to me, in Allah's name, that ye will be sure to bring him back to me unless ye are yourselves hemmed in (and made powerless). And when they had sworn their solemn oath, he said: "Over all that we say, be Allah the witness and guardian!"

(13) So warn mankind of the Day when the Wrath will reach them: then will the wrong-doers say: "Our Lord! respite us (if only) for a short term: we will answer Thy call, and follow the messengers!" "What! were ye not wont to swear aforetime that ye should suffer no decline?

(14) They swear their strongest oaths by Allah, that Allah will not raise up those who die: Nay, but it is a promise (binding) on Him in truth: but most among mankind realise it not.

(15) They swear their strongest oaths by Allah that, if only thou wouldst command them, they would leave (their homes). Say: "swear ye not; Obedience is (more) reasonable; verily, Allah is well acquainted with all that ye do."

(16) They said: "swear a mutual oath by Allah that we shall make a secret night attack on him and his people, and that we shall then say to his heir (when he seeks vengeance): 'We were not present at the slaughter of his people, and we are positively telling the truth.'"

(17) On the Day that the Hour (of Reckoning) will be established, the transgressors will swear that they tarried not but an hour: thus were they used to being deluded!

(18) Turnest thou not thy attention to those who turn (in friendship) to such as have the Wrath of Allah upon them? They are neither of you nor of them, and they swear to falsehood knowingly.

(19) One day will Allah raise them all up (for Judgment): then will they swear to Him as they swear to you: And they think that they have something (to stand upon). No, indeed! they are but liars!