The word(s) "oath" appears 29 time(s) in 25 verse(s) in Quran in Muhammad Pickthal translation.

(21) O Prophet! If believing women come unto thee, taking oath of allegiance unto thee that they will ascribe no thing as partner unto Allah, and will neither steal nor commit adultery nor kill their children, nor produce any lie that they have devised between their hands and feet, nor disobey thee in what is right, then accept their allegiance and ask Allah to forgive them. Lo! Allah is Forgiving, Merciful.

(22) Allah hath made lawful for you (Muslims) absolution from your oaths (of such a kind), and Allah is your Protector. He is the Knower, the Wise.

(23) Neither obey thou each feeble oath-monger,

(24) Or have ye a covenant on oath from Us that reacheth to the Day of Judgment, that yours shall be all that ye ordain?

(25) There surely is an oath for thinking man.