The Cow - 2:42
Do not knowingly confuse the truth with falsehood, and do not conceal the truth.
Our Lord's judgment on those who conceal something from the Book:
The Cow/2:174
Those who conceal something from the Book which Allah has sent down and exchange it for a little, they are stuffing fire in their bellies. Allah will not speak to them on the Day of Resurrection nor purify them. For them is a painful torment.
The Cow/2:175
They have bought error for guidance and torment for forgiveness. How resistant they are to the fire!
The Cow/2:159
Those who conceal the clear proofs and guidance which We have sent down - after We have made it public in the Book - are cursed by Allah and all those who curse.
Explained in Detail/41:40
Those who distort Our Verses are not hidden from Us. Who is better, he who is thrown into the Fire or he who comes to Us on the Day of Resurrection in safety? Act as you wish. Surely He is the All-Seeing of what you do.
Prophet Jonah/10:15
"When Our clear Verses are recited to them, those who do not hope to meet Us say: "Bring another Qur´an other than this, or change it!"Say: "I cannot change it from my own side. I follow only what has been revealed to me. If I disobey my Lord, I fear the punishment of a great Day."
The Cow/2:211
Ask the Children of Israel, how many clear signs We gave them! Allah will inflict a severe punishment on those who change the favor of Allah after it has come to them.
The Night Journey/17:73
They would almost have led you astray from what We have revealed to you so that you might invent something else and attribute it to Us. Then they would have taken you as a friend.
The Night Journey/17:74
If We had not made you firm, you would almost have inclined to them a little
The Night Journey/17:75
Then We would have made you taste the torment of life and death multiplied, then you would not have found any helper against Us.