The word(s) "secret" appears 40 time(s) in 40 verse(s) in Quran in Muhammad Pickthal translation.

(31) Or do those in whose hearts is a disease deem that Allah will not bring to light their (secret) hates?

(32) If He should ask it of you and importune you, ye would hoard it, and He would bring to light your (secret) hates.

(33) Who feareth the Beneficent in secret and cometh with a contrite heart.

(34) Hast thou not seen that Allah knoweth all that is in the heavens and all that is in the earth? There is no secret conference of three but He is their fourth, nor of five but He is their sixth, nor of less than that or more but He is with them wheresoever they may be; and afterward, on the Day of Resurrection, He will inform them of what they did. Lo! Allah is Knower of all things.

(35) O ye who believe! Choose not My enemy and your enemy for allies. Do ye give them friendship when they disbelieve in that truth which hath come unto you, driving out the messenger and you because ye believe in Allah, your Lord? If ye have come forth to strive in My way and seeking My good pleasure, (show them not friendship). Do ye show friendship unto them in secret, when I am Best Aware of what ye hide and what ye proclaim? And whosoever doeth it among you, he verily hath strayed from the right way.

(36) Lo! those who fear their Lord in secret, theirs will be forgiveness and a great reward.

(37) And keep your opinion secret or proclaim it, lo! He is Knower of all that is in the breasts (of men).

(38) On that day ye will be exposed; not a secret of you will be hidden.

(39) (He is) the Knower of the Unseen, and He revealeth unto none His secret,

(40) And the secrets of the breasts are made known,