The following are only a few of the important sayings from the Koran, dealing with kafirs or infidels. There are many more similar sayings throughout Islam's holy book. The message is the same. The numbers of chapters and verses are indicated in Roman and Hindu (or Arabic) numerals on the left. The injunctions are clearly spelled out so that there is no misunderstanding in the minds of simple believers.

VIII/12:
When thy Lord inspired the angels, (saying:) I am with you. So make those who believe stand firm. I will throw fear into the hearts of those who disbelieve. Then smite the necks and smite of them each finger [1].

VIII/36:
Lo! those who disbelieve spend their wealth in order that they may debar (men) from the way of Allah. They will spend it, then it will become an anguish for them, then they will be conquered. And those who disbelieve will be gathered unto hell.

IX/5:
Then, when the sacred months have passed, slay the idolaters wherever ye find them, and take them (captive), and besiege them, and prepare for them each ambush. But if they repent and establish worship and pay the poor-due, then leave their way free. Lo! Allah is Forgiving, Merciful.

IX/28:
O ye who believe! The idolaters only are unclean. So let them not come near the Inviolable Place of Worship after this their year. If ye fear poverty (from the loss of their merchandise) Allah shall preserve you of His bounty if He will. Lo! Allah is Knower, Wise.
IX/73:
Oh Prophet! Strive against the disbelievers and the hypocrites! Be harsh with them. Their ultimate abode is hell, a hapless journey's-end.

XCVIII/6:
Lo! those who disbelieve, among the People of the Scripture and the idolaters, will abide in fire of hell. They are the worst of created beings.

X/5:
Unto Him is the return of all of you; it is a promise of Allah in truth. Lo! He produceth creation, then reproduceth it, that He may reward those who believe and do good works with equity; while, as for those who disbelieve, theirs will be a boiling drink and painful doom because they disbelieved.

LXIX/30-37:
(It will be said): Take him and fetter him And then expose him to hell-fire And then insert him in a chain whereof the length is seventy cubits. Lo! he used not to believe in Allah the Tremendous, And urged not on the feeding of the wretched, Therefore hath he no lover here this day, Nor any food save filth Which none but sinners eat.

LXVIII/14-16:
It is because he is possessed of wealth and children That, when Our revelations are recited unto him, he saith: Mere fables of the men of old. We shall brand him on the nose.

LXVII/6:
And for those who disbelieve in their Lord there is the doom of hell, a hapless journey's end!

XLVII/12:
Lo! Allah will cause those who believe and do good works to enter Gardens underneath which rivers flow; while those who disbelieve take their comfort in this life and eat even as the cattle eat, and the Fire is their habitation.

XLIV/43-50:
Lo! the tree of Zaqqum [2], The food of the sinner! Like molten brass, it seetheth in their bellies As the seething of boiling water. (And it will be said): Take him and drag him to the midst of hell, Then pour upon his head the torment of boiling water. (Saying): Taste! Lo! thou west forsooth the mighty, the noble! Lo! this is that whereof ye used to doubt.

XXXVII/67-68:
And afterward, lo! thereupon they have a drink of boiling water And afterward, lo! their return is surely unto hell.

V/33-34:
The only reward of those who make war upon Allah and His messenger and strive after corruption in the land will be that they will be killed or crucified, or have their hands and feet on alternate sides cut off, or will be expelled out of the land. Such will be their degradation in the world, and in the Hereafter theirs will be an awful doom; Save those who repent before ye overpower them. For know that Allah is Forgiving, Merciful.

V/72-73:
They surely disbelieve who say: Lo! Allah is the Messiah, son of Mary. The Messiah (himself) said: O Children of Israel, worship Allah, my Lord and your Lord. Lo! whoso ascribeth partners unto Allah, for him Allah bath forbidden Paradise. His abode is the Fire. For evil-doers there will be no helpers. They surely disbelieve who say: Lo! Allah is the third of three; when there is no God save the One God. If they desist not from so saying a painful doom will fall on those of them who disbelieve.

XXII/19-22:
These twain (the believers and the disbelievers) are two opponents who contend concerning their Lord. But as for those who disbelieve, garments of fire will be cut out for them; boiling fluid will be poured down on their heads. Whereby that which is in their bellies, and their skins too, will be melted; And for them are hooked rods of iron. Whenever, in their anguish, they would go forth from thence they are driven back therein and (it is said unto them): Taste the doom of burning.

LXXVI/4:
Lo! We have prepared for disbelievers manacles and carcans and a raging fire.

Footnotes

1. N.J. Dawood translates in his 'The Koran': 'Strike off their heads, maim them in every limb!'
2. Zaqqum tree: a tree that grows in the heart of hell bearing fruit like devils' heads.