The word(s) "secret" appears 15 time(s) in 15 verse(s) in Quran in Saheeh International translation.

(1) There is no blame upon you for that to which you [indirectly] allude concerning a proposal to women or for what you conceal within yourselves. Allah knows that you will have them in mind. But do not promise them secretly except for saying a proper saying. And do not determine to undertake a marriage contract until the decreed period reaches its end. And know that Allah knows what is within yourselves, so beware of Him. And know that Allah is Forgiving and Forbearing.

(2) Those who spend their wealth [in Allah 's way] by night and by day, secretly and publicly - they will have their reward with their Lord. And no fear will there be concerning them, nor will they grieve.

(3) And whoever among you cannot [find] the means to marry free, believing women, then [he may marry] from those whom your right hands possess of believing slave girls. And Allah is most knowing about your faith. You [believers] are of one another. So marry them with the permission of their people and give them their due compensation according to what is acceptable. [They should be] chaste, neither [of] those who commit unlawful intercourse randomly nor those who take [secret] lovers. But once they are sheltered in marriage, if they should commit adultery, then for them is half the punishment for free [unmarried] women. This [allowance] is for him among you who fears sin, but to be patient is better for you. And Allah is Forgiving and Merciful.

(4) This day [all] good foods have been made lawful, and the food of those who were given the Scripture is lawful for you and your food is lawful for them. And [lawful in marriage are] chaste women from among the believers and chaste women from among those who were given the Scripture before you, when you have given them their due compensation, desiring chastity, not unlawful sexual intercourse or taking [secret] lovers. And whoever denies the faith - his work has become worthless, and he, in the Hereafter, will be among the losers.

(5) And He is Allah, [the only deity] in the heavens and the earth. He knows your secret and what you make public, and He knows that which you earn.

(6) Did they not know that Allah knows their secrets and their private conversations and that Allah is the Knower of the unseen?

(7) And those who are patient, seeking the countenance of their Lord, and establish prayer and spend from what We have provided for them secretly and publicly and prevent evil with good - those will have the good consequence of [this] home -

(8) [O Muhammad], tell My servants who have believed to establish prayer and spend from what We have provided them, secretly and publicly, before a Day comes in which there will be no exchange, nor any friendships.

(9) Allah presents an example: a slave [who is] owned and unable to do a thing and he to whom We have provided from Us good provision, so he spends from it secretly and publicly. Can they be equal? Praise to Allah! But most of them do not know.

(10) And if you speak aloud - then indeed, He knows the secret and what is [even] more hidden.