The word(s) "conceal" appears 36 time(s) in 35 verse(s) in Quran in Abdullah Yusuf Ali translation.

(21) It is the same (to Him) whether any of you conceal his speech or declare it openly; whether he lie hid by night or walk forth freely by day.

(22) "O our Lord! truly Thou dost know what we conceal and what we reveal: for nothing whatever is hidden from Allah, whether on earth or in heaven.

(23) And Allah doth know what ye conceal, and what ye reveal.

(24) Undoubtedly Allah doth know what they conceal, and what they reveal: verily He loveth not the arrogant.

(25) Their hearts toying as with trifles. The wrong-doers conceal their private counsels, (saying), "Is this (one) more than a man like yourselves? Will ye go to witchcraft with your eyes open?"

(26) It is no fault on your part to enter houses not used for living in, which serve some (other) use for you: And Allah has knowledge of what ye reveal and what ye conceal.

(27) And thy Lord knows all that their hearts conceal and all that they reveal.

(28) Whether ye reveal anything or conceal it, verily Allah has full knowledge of all things.

(29) (Allah) knows of (the tricks) that deceive with the eyes, and all that the hearts (of men) conceal.

(30) A believer, a man from among the people of Pharaoh, who had concealed his faith, said: "Will ye slay a man because he says, 'My Lord is Allah'?- when he has indeed come to you with Clear (Signs) from your Lord? and if he be a liar, on him is (the sin of) his lie: but, if he is telling the Truth, then will fall on you something of the (calamity) of which he warns you: Truly Allah guides not one who transgresses and lies!