The word(s) "secret" appears 51 time(s) in 49 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) He said: "O Adam! Tell them their names." When he had told them, Allah said: "Did I not tell you that I know the secrets of heaven and earth, and I know what ye reveal and what ye conceal?"

(2) Permitted to you, on the night of the fasts, is the approach to your wives. They are your garments and ye are their garments. Allah knoweth what ye used to do secretly among yourselves; but He turned to you and forgave you; so now associate with them, and seek what Allah Hath ordained for you, and eat and drink, until the white thread of dawn appear to you distinct from its black thread; then complete your fast Till the night appears; but do not associate with your wives while ye are in retreat in the mosques. Those are Limits (set by) Allah: Approach not nigh thereto. Thus doth Allah make clear His Signs to men: that they may learn self-restraint.

(3) There is no blame on you if ye make an offer of betrothal or hold it in your hearts. Allah knows that ye cherish them in your hearts: But do not make a secret contract with them except in terms Honourable, nor resolve on the tie of marriage till the term prescribed is fulfilled. And know that Allah Knoweth what is in your hearts, and take heed of Him; and know that Allah is Oft-forgiving, Most Forbearing.

(4) Those who (in charity) spend of their goods by night and by day, in secret and in public, have their reward with their Lord: on them shall be no fear, nor shall they grieve.

(5) Ah! ye are those who love them, but they love you not,- though ye believe in the whole of the Book. When they meet you, they say, "We believe": But when they are alone, they bite off the very tips of their fingers at you in their rage. Say: "Perish in your rage; Allah knoweth well all the secrets of the heart."

(6) After (the excitement) of the distress, He sent down calm on a band of you overcome with slumber, while another band was stirred to anxiety by their own feelings, Moved by wrong suspicions of Allah-suspicions due to ignorance. They said: "What affair is this of ours?" Say thou: "Indeed, this affair is wholly Allah's." They hide in their minds what they dare not reveal to thee. They say (to themselves): "If we had had anything to do with this affair, We should not have been in the slaughter here." Say: "Even if you had remained in your homes, those for whom death was decreed would certainly have gone forth to the place of their death"; but (all this was) that Allah might test what is in your breasts and purge what is in your hearts. For Allah knoweth well the secrets of your hearts.

(7) Allah will not leave the believers in the state in which ye are now, until He separates what is evil from what is good nor will He disclose to you the secrets of the Unseen. But He chooses of His Messengers (For the purpose) whom He pleases. So believe in Allah. And His messengers: And if ye believe and do right, ye have a reward without measure.

(8) In most of their secret talks there is no good: But if one exhorts to a deed of charity or justice or conciliation between men, (Secrecy is permissible): To him who does this, seeking the good pleasure of Allah, We shall soon give a reward of the highest (value).

(9) This day are (all) things good and pure made lawful unto you. The food of the People of the Book is lawful unto you and yours is lawful unto them. (Lawful unto you in marriage) are (not only) chaste women who are believers, but chaste women among the People of the Book, revealed before your time,- when ye give them their due dowers, and desire chastity, not lewdness, nor secret intrigues if any one rejects faith, fruitless is his work, and in the Hereafter he will be in the ranks of those who have lost (all spiritual good).

(10) And call in remembrance the favour of Allah unto you, and His covenant, which He ratified with you, when ye said: "We hear and we obey": And fear Allah, for Allah knoweth well the secrets of your hearts.