Surely those who conceal the clear proofs and the guidance that We revealed after We made it clear in the Book for men, these it is whom Allah shall curse, and those who curse shall curse them (too).

And when Allah made a covenant with those who were given the Book: You shall certainly make it known to men and you shall not hide it; but they cast it behind their backs and took a small price for it; so evil is that which they buy.

O you who believe! call to witness between you when death draws nigh to one of you, at the time of making the will, two just persons from among you, or two others from among others than you, if you are travelling in the land and the calamity of death befalls you; the two (witnesses) you should detain after the prayer; then if you doubt (them), they shall both swear by Allah, (saying): We will not take for it a price, though there be a relative, and we will not hide the testimony of Allah for then certainly we should be among the sinners.

And a believing man of Firon's people who hid his faith said: What! will you slay a man because he says: My Lord is Allah, and indeed he has brought to you clear arguments from your Lord? And if he be a liar, on him will be his lie, and if he be truthful, there will befall you some of that which he threatens you (with); surely Allah does not guide him who is extravagant, a liar: